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Few-unit cell thick Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (Bi-2212) layers have recently attracted much interest due to their extreme anisotropy and two-dimensional superconductivity although they are typically susceptible to ambient conditions we report on thin films approximately 13 unit cells thick that are stable in air and demonstrate extraordinarily high critical currents By examining the superconducting transition under magnetic fields applied in both out-of-plane and in-plane orientations we estimate key parameters such as pinning potentials The volume pinning force is better described by a model incorporating an exponential decay term attributed to pronounced thermally-assisted flux flow The Hall effect in the Bi-2212 films exhibits an extensive anomaly with a double sign change that may challenge existing theoretical explanations for this poorly understood phenomenon in copper-oxide superconductors The investigation of high-temperature superconductivity in copper-oxide materials remains one of the most captivating subjects in condensed matter physics One member of the family of these superconductors the compound Bi$_2$Sr$_2$CaCu$_2$O$_{8+x}$ (Bi-2212) stands out due to its weakly coupled layered structure that gives rise to the highest anisotropy in this class of materials The unit cell of Bi-2212 is composed of two diagonally shifted subcells each incorporating the nominal chemical formula These distinctive features make it an exemplary system for exploring quasi-two-dimensional superconductivity Extending these concepts to very thin films with larger areas and easier fabrication options may be an interesting future development Current studies are underway to extend this technique to thin Bi-2212 films which must have a thickness of less than about 50 nm to allow full penetration of the employed 30 keV He$^+$ ions This study aims to provide valuable data on very thin Bi-2212 films by measurements of the anisotropic magnetoresistance with the magnetic field oriented perpendicular and parallel to the CuO$_2$ layers; the latter has been rarely explored so far Critical current and Hall effect measurements provide additional insights into the transport properties of our samples By presenting a detailed analysis of the electrical transport properties of Bi-2212 and providing estimates for the most important superconducting material parameters we seek to contribute to the fundamental background to inspire future applications in electronic devices harnessing these remarkable materials Vortex pinning energy $U/k_{\mathrm{B}}$, expressed in temperature units, determined from the fits to Eq. (1) using the data displayed in Fig. 2 (sample A). The lines represent power-law fits to the resulting U(B) dependencies. (a) Hall coefficient measured in multiple magnetic fields applied perpendicular to the ab planes of the Bi-2212 thin film (sample B). The inset provides a magnified view to emphasize the sign reversal of the Hall effect. (b) Normalized Hall conductivity $\sigma _{xy}/B$ as a function of temperature under various magnetic fields. The grey dashed line illustrates a $T^{-2}$ dependence of the normal-state $\sigma _{xy}/B$. Inset: Detailed view of the Hall effect sign change. Reciprocal tangent of the Hall angle plotted as a function of the squared temperature (Sample B) Cross-sectional transmission electron microscopy (TEM) analysis confirmed the excellent epitaxial growth and layered structure of our thin Bi-2212 films. The half unit-cell periodicity is clearly visible in Fig. 1b indicating that this 49-nm-thick Bi-2212 film consists of 16 unit cells stacked along the c direction The number of layers corresponds to a calculation using the crystallographic unit cell parameters and the thickness of the film as determined by atomic force microscopy (AFM) The TEM image reveals some structural defects at the interface of Bi-2212 film and LAO ($a_{\mathrm{LAO}} = 3.82$ Å) crystal substrate TEM images of our Bi-2212 films with 13 unit cell thickness on (LaAlO$_3$)$_{0.3}$(Sr$_2$TaAlO$_6$)$_{0.7}$ (LSAT $a_{\mathrm{LSAT}} = 3.87$ Å) substrates were very similar and showed the same layered structure of Bi-2212 and very similar nanoscopic defects at the film-substrate interface defined by the inflection point where ${\mathrm{d}}^2 \rho _{xx}/ {\mathrm{d}}T^2=0$ is $T_{c,inf}= 90.0$ K (sample A) and $T_{c,inf}= 88.0$ K (sample B) A linear extrapolation of the normal-state $\rho _{xx}(T)$ behaviour to $\rho _{xx}(T)=0$ yields slightly negative intercepts of about − 30 K (sample A) and − 20 K (sample B) This demonstrates that the substantial reduction in film thickness does not significantly increase the resistivity these characteristics are consistent with those expected from high-quality optimally doped copper-oxide superconductors Despite having a thickness of about 13 unit cells, our Bi-2212 films demonstrate remarkable stability. Following the initial measurement, we re-examined the temperature dependence of the resistivity of sample B after 319 days. This is illustrated as solid and dashed lines in Fig. 1a including temperature cycling in both a vacuum and a helium atmosphere for various investigations and stored in a desiccator with dry air at room temperature the critical temperature experienced a drop of $\Delta T_{\mathrm{c,inf}} = 2.8\,{\mathrm{K}}$ and the normal state resistivity increased by 5% at 150 K An Arrhenius plot of the magnetoresistivity, shown in Fig. 2a reveals linear behaviour for $T\lesssim 91$ K indicative of thermally-assisted flux flow (TAFF) thereby underscoring the distinct vortex dynamics associated with Josephson-coupled pancake vortices in Bi-2212 compared to conventional Abrikosov vortices in RE-123 and it decreases far more slowly as B increases One possible explanation for the observed difference is related to the significantly greater thickness of single crystals compared to our very thin films the magnetic field may not penetrate uniformly into single crystals this penetration is much more effective in thin films ensuring that the pinning potential in each layer is fully active The results for sample A are $B_{\mathrm{c2}}^{\perp }(0)\approx 106$ T and $B_{\mathrm{c2}}^{\parallel }(0) \approx 19,000$ T revealing an anisotropy parameter $\gamma =B_{\mathrm{c2}}^{\parallel }(0)/B_{\mathrm{c2}}^{\perp }(0) \approx 180$ For sample B we find $B_{\mathrm{c2}}^{\perp }(0)\approx 86$ T Our even smaller estimate for $\xi _{c}$ confirms the excellent CuO$_2$-layer stacking in our films and can be attributed to the careful alignment of the magnetic field with these layers The inset shows that the data conform well to the relation where $J_{{\mathrm{c}}}^{{\mathrm{sf}}}$ is determined by the lower critical field as $J_{{\mathrm{c}}}^{{\mathrm{sf}}}=H_{\mathrm{c1}}^{\perp } / \lambda _{ab}$ leading to an expression confirmed in many superconducting materials the extrapolation to $T=0$ yields $J_{\mathrm{c}}^{\mathrm{sf}}(0) \approx 8.1\,\mathrm {MA/cm}^2$ an accompanying estimate of the minimum $J_{\mathrm{c}}^{\mathrm{sf}}(0)$ in our two Bi-2212 films is also warranted low-temperature measurements revealed $J_{\mathrm{c}}^{\mathrm{sf}}(6\,{\mathrm{K}}) = 5.1\,\mathrm {MA/cm}^2$ in sample B though this value is subject to some uncertainty due to heating from dissipation at the current contacts any systematic temperature error would lead to an underestimate of $J_{{\mathrm{sf}}}(0)$ thereby reinforcing our conservative lower-limit estimate of $J_{\mathrm{c}}^{\mathrm{sf}}(0) \ge 5.1\,\mathrm {MA/cm}^2$ where the main panel presents $J_c(B)$ on a linear scale and the inset shows the same data on a semi-logarithmic scale at $45\,{\mathrm{K}} \sim T_{\mathrm{c}}/2$ $J_{\mathrm{c}}$ diminishes approximately one order of magnitude up to 1 T about half of our sample A’s value of $J_{{\mathrm{c}}}^{{\mathrm{sf}}}(50\,{\mathrm{K}})=2.2\,\mathrm {MA/cm}^2$ the lattice mismatch with the LAO substrate induces a uniform misfit strain that relaxes by forming structural defects complete relaxation of misfit strain occurs only at some distance from the interface which makes a higher density of defects more likely in thinner films this could result in higher $J_{\mathrm{c}}$ values compared to thicker films $B^*$ corresponds to $B_{\mathrm{c2}}.$ For HTS it is more appropriately associated with the irreversibility field $B_\mathrm{irr}.$ $F_{\mathrm{p}}^*$ is a temperature-dependent scaling parameter while the dimensionless exponents p and q reflect the specific nature and dimensionality of the pinning centres—whether they are point-like Figure 4c shows the field dependence of the volume pinning force $F_{\mathrm{p}}(B,T)$ which exhibits the characteristic shape commonly observed in HTS the maximum pinning force $F_{\mathrm{p}}^\mathrm{max}$ in Bi-2212 thin films is notably smaller and occurs at approximately one-tenth the magnetic field B This shift and reduction are not unexpected given the substantially weaker pinning of two-dimensional pancake-like vortices in Bi-2212 and the absence of strong micro-twin-boundary-induced pinning centres that are known to enhance $F_{\mathrm{p}}(B,T)$ in YBCO underscoring the intricate interplay between the normal-state and superconducting regimes in these materials We attribute our higher value to an increased density of scattering defects possibly arising from lattice mismatch at the substrate interface which cannot fully relax in ultra-thin films may create stacking faults that lead to stronger vortex pinning and thus explain the exceptionally high critical currents observed in our samples The amplitude of the negative $R_{\mathrm{H}}$ peak decreases markedly with increasing $B_z$, and by $B_z \ge 6$ T, the sign change disappears. Still, a minor dip remains visible in the inset of Fig. 6a the negative Hall signal surpasses even the maximum positive $R_{\mathrm{H}}$ observed in the normal state This effect is far more pronounced in our very thin Bi-2212 films than reported elsewhere probably challenging theoretical models of the Hall anomaly based on the normal-state Hall effect in the cores of vortices Our findings may encourage further attempts to distinguish between the proposed mechanisms for the Hall anomaly The model is based on superconducting order-parameter fluctuations and a low-temperature cutoff by a diverging $\sigma _{xx}$ due to pinning and we also see it in our approximately 13-unit-cell-thick films at similar temperatures More studies are required to clarify the origin of this phenomenon in Bi-2212 could be an excellent material for this endeavour Finally, Table 1 summarizes the parameters obtained from our various measurements Despite apparent differences between fabrication of the two samples the fundamental superconducting parameters including the upper critical field $B_{\mathrm{c2}}^{ab}(0)$ London penetration depth $\lambda _{\mathrm{L}}^{ab}$ and the Ginzburg–Landau parameter $\kappa$ This consistency underscores the reproducibility of our results and provides a solid foundation for future studies on the properties of few-unit-cell thin Bi-2212 films a substrate temperature of $T = 780\,^\circ$C and oxygen background pressure of $p(\text {O}_2) = 1.2$ mbar was used Post-deposition in-situ annealing of the films at $T = 600\,^\circ$C ensured optimally-doped samples Single-crystalline (0 0 1) LaAlO$_3$ substrates with a lattice parameter $a_L = 3.82$ Å were used The number of laser pulses (500 and 600 for films below 50 nm thickness) controls the film thickness which was measured by AFM after UV-photolithographic structuring and wet-chemical etching The phase purity and orientation of the deposited films were analysed via X-ray diffraction (XRD) with Cu K$\alpha$ radiation; $\theta$-$2\theta$-scans were performed to verify the c-axis orientation of deposited films The phase purity of the deposited Bi-2212 thin films which can often suffer from the low-$T_{\mathrm{c}}$ phase ingrowth of Bi$_2$Sr$_2$CuO$_y$ thin epitaxial Bi-2212 film were grown on LAO and LSAT substrates and covered by a Pt-C protective layer before a focused gallium ion beam (Ga-FIB) was used to cut a thin lamella Short imaging times of only a few minutes were used to not deteriorate the atomic structure as longer times led to a complete amorphization of the film material circular contact pads were established by evaporating Ag/Au pads (for optimal adhesion on the Bi-2212 film) through a copper shadow mask the thin films with thicknesses 46 nm (42 nm) were patterned into rectangular-shaped bridges of $63\,\upmu$m ($102\,\upmu$m) width and $94\,\upmu$m ($497\,\upmu$m) distance between the voltage probes for sample A (sample B) by UV photolithography and wet chemical etching Sample B was post-annealed in oxygen after patterning (400$\,^\circ$C for 30 min in 0.8 mbar oxygen atmosphere) Electrical contacts in the cryostat were established using silver paste and $50\,\upmu$m thick gold wires For all orientations of the magnetic field the transport current was perpendicular to the field Measurements in zero or low magnetic fields were performed in a cryocooler placed between the pole pieces of an electromagnet The critical current was determined under isothermal and constant magnetic field conditions by increasing the current in small steps up to an electric field criterion of $10\,\upmu$V/cm (corresponding to 100 nV for sample A and 500 nV for sample B) and interpolating between data points Data at intense currents and low temperatures were excluded when the PPMS indicated a temperature rise due to sample heating by finite contact resistances The Hall voltage $V_y$ was collected during temperature sweeps at fixed magnetic fields in both polarities $B^+$ and $B^-$ and calculated as $V_y = (V_{B^+} - V_{B^-})/2$ Occasional magnetic field sweeps confirmed the accuracy of this method The data generated and analysed during this study are available from the corresponding author upon reasonable request Samoilov, A. 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Solid State Commun. 70, 291–295. https://doi.org/10.1016/0038-1098(89)90330-x (1989) Download references Talantsev for illuminating discussions and to W by the Austrian Science Fund (FWF) Grant-DOI: 10.55776/I4865 the authors have applied a CC BY public copyright license to any Author Accepted Manuscript version arising from this submission acknowledges financial support from the Austrian Science Fund This article is based upon work from COST Actions SuperQuMap CA21144 and Polytopo CA23134 (European Cooperation in Science and Technology) Bernd Aichner and Sandra Keppert contributed equally to this work drafted the manuscript and all authors contributed to the manuscript and reviewed it The authors declare no competing interests Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations Download citation DOI: https://doi.org/10.1038/s41598-025-95932-9 Anyone you share the following link with will be able to read this content: a shareable link is not currently available for this article Sign up for the Nature Briefing newsletter — what matters in science Metrics details Copper oxide high-temperature superconductors have garnered extensive research interest due to their high critical temperatures (Tc) surpassing the Bardeen–Cooper–Schrieffer (BCS) limit The two-dimensional CuO₂ plane is widely regarded as the most crucial element of high-Tc cuprate superconductors The anisotropy of this CuO₂ layer remains a topic of ongoing interest Although a few experimental results have reported strong optical anisotropy in both ab and ac-planes of Bi2212 through optical “reflectivity” measurements there is a lack of studies focusing on the optical anisotropy of these materials using optical “transmittance” measurements by utilizing ultraviolet and visible light Using a generalized high-accuracy universal polarimeter we observed significant linear birefringence and linear dichroism peaks in the UV region at room temperature To investigate the origin of the significant optical anisotropy single crystals of Bi2−xPbxSr2CaCu2O8+δ with different lead contents (x = 0 and 0.6) were grown using the floating zone method and the wavelength dependencies of linear birefringence and linear dichroism along the c axis were measured The insights gained into the optical anisotropy of Bi2−xPbxSr2CaCu2O8+δ from this study are significant for discussing its origin of the mechanism of high-Tc superconductivity The mechanism responsible for the formation of Cooper pairs is not explained by electron–phonon interactions of BCS theory remaining one of the big mysteries in the field of physics which the anisotropy was attributed to the quasi-one-dimensional CuO chains Bi2Sr2CaCu2O8+δ (Bi2212) provides a better opportunity to study the intrinsic anisotropy as there are no chains in these Bi-based cuprates While reflectivity measurements also contribute to understanding of “bulk properties” of the material there is a lack of studies focusing on the optical anisotropy of these materials using optical “transmittance” measurements which more directly provide us the insight Considering the suggestion that strong electron-phonon interaction may become a key mechanism for superconductivity in high-temperature superconductors (HTSCs) it may be essential to scrutinize the characteristics of phonons and/or low-energy excitation properties in these materials more thoroughly by utilizing ultraviolet (UV) and visible (Vis) light as optical probes it is possible to simultaneously obtain insights into the electromagnetic properties of these materials which specifically relating to “transitions of outer shell electrons.” These transitions can reveal crucial information about the electronic band structure the origin of the large LB and LD may be from the incommensurate modulation along the b axis single crystals of Bi2−xPbxSr2CaCu2O8+δ with varying lead contents (x = 0 and 0.6) were grown using the floating zone (FZ) method and the wavelength dependences of the LB and LD along the c axis were examined using G-HAUP to clarify whether the origin of the large LB and LD is from incommensurate modulation Any anneal treatment was not applied in this study The actual composition of the samples prepared by dissolving the crystals in nitric acid was determined by inductively coupled plasma optical emission spectrometry (ICP-OES) ICP-OES measurements were conducted using an Agilent 5100 instrument (Agilent Technologies) The actual ratios of Bi:Pb:Sr:Ca:Cu determined by ICP-OES were 1.61:0.41:1.76:1.00:1.84 for x = 0.4 and 1.41:0.61:1.79:1.00:1.74 for x = 0.6 (with Ca set to 1.00) The crystal structure of the Bi2−xPbxSr2CaCu2O8+δ was characterized by XRD with Cu Kα radiation (λ = 1.5418 Å) X-ray photoelectron spectroscopy (XPS) measurements were performed using a JPS-9010TR (JEOL) with a nonmonochromatic Mg Kα (1253.6 eV) X-ray source The confirmation of whether the incommensurate modulations of Bi2−xPbxSr2CaCu2O8+δ were suppressed was verified through scanning transmission electron microscopy (STEM) observation and electron diffraction STEM images were acquired using a JEM-ARM300F (JEOL) for focused ion beam specimens at an accelerating voltage of 300 kV The temperature dependence of the magnetic susceptibility was measured using a superconducting quantum interference device (SQUID) to determine Tc SQUID measurements were conducted using a VSM SQUID (Quantum Design) were prepared by exfoliating crystals with a water-soluble tape The specimens were then mounted on a stainless-steel pinhole plate to enhance the signal-to-noise ratio of the transmitted light intensity To confirm whether the specimens consisted of a single domain The thicknesses of the specimens were measured using field emission-scanning electron microscopy (FE–SEM; SU-8240 Hitachi High-Tech) and were found to be almost identical to those measured by atomic force microscopy (SPM-9700 and SQUID (C) measurements of the Bi2−xPbxSr2CaCu2O8+δ with three typical Pb contents x = 0 (black) the intensities of some of the peaks indicated by * marks (at 2θ of ~ 25.9° and ~ 55.2°) increased with increasing Pb content probably owing to the slight changes in the atomic arrangement and chemical bonding in the crystals and electron diffraction images (B) along the [100] axis of the Bi2−xPbxSr2CaCu2O8+δ with three typical Pb contents x = 0 (top) Thin (001) plate specimens with a diameter of approximately 0.2 mm were prepared by exfoliating the crystal. For each Pb content (x = 0, 0.4 and 0.6), ultrathin (001) plate specimens were prepared. Utilizing a polarized light microscope, we confirmed that these specimens were single domain and exhibited high homogeneity, as illustrated in Fig. 3A This high homogeneity facilitates high-precision LB and LD measurements we observed a decrease in optical anisotropy with increasing Pb content The thicknesses of the specimens were estimated to be 457 nm Despite the x = 0 sample being thinner than the x = 0.4 or 0.6 sample clear addition and subtraction phenomena were observed with a λ plate even in the thinner x = 0 sample the comparative analysis of polarized light microscopic images between x = 0 and 0.4 or 0.6 specimens provide qualitative yet direct evidence of the decrease in optical anisotropy with increasing Pb content The consistent monotonic decrease in LB and LD magnitudes with increasing Pb content suggests that the origin of LB and LD is associated with incommensurate modulation along the b axis (A) Polarized light microscope images with different azimuth angles θ of the Bi2−xPbxSr2CaCu2O8+δ with x = 0 (top) D) Wavelength dependences of LB (B) and LD (C) and absorbance (D) of the Bi2−xPbxSr2CaCu2O8+δ with x = 0 (black) The values and error bars of LB and LD were derived from the average value and standard deviation for five specimens with different thicknesses Tauc plots of each absorption spectrum are depicted in the inset of (D) we try to explore the question of whether the spatial-inversion symmetry and time-reversal symmetry are broken in the pseudogap and superconducting phases The data used and/or analyzed during the current study available from the corresponding author on reasonable request Possible high Tc superconductivity in the Ba-La-Cu-O system From quantum matter to high-temperature superconductivity in copper oxides Direct measurement of the anisotropy of the resistivity in the a-b plane of twin-free a-b anisotropy of the normal-state resistivity of untwinned YBa2Cu3O7–δ T2 dependence of the resistivity in the Cu-O chains of YBa2Cu3O6.9 Anisotropy of the reflectance spectrum and of the dielectric function of YBa2Cu3O7 within the (001) plane Superconducting energy gap and normal-state conductivity of a single-domain YBa2Cu3O7 crystal Far-infrared absorptivity of single-domain YBa2Cu3O7 Dependence of the infrared properties of single-domain YBa2Cu3O7–y on oxygen content Development of the optical conductivity with doping in single-domain YBa2Cu3O6+x In-Plane Anisotropy of the Penetration Depth in YBa2Cu3O7–x and YBa2Cu4O8 Superconductors Measurement of the ab plane anisotropy of microwave surface impedance of untwinned YBa2Cu3O6.95 single crystals Optical evidence for strong anisotropy in the normal and superconducting states in Bi2Sr2CaCu2O8+ z A systematic optical study of phonon properties in optimally doped Bi2Sr2CaCu2O8+δ single crystals Optical study of an untwinned (Bi1.57Pb0.43)Sr2CaCu2O8+δ single crystal: ab-plane anisotropy Optical properties of superconducting Bi2Sr2CaCu2O8 An application of the advanced high-accuracy universal polarimeter to the chiroptical measurement of an intercalated compound K4Nb6O17 with high anisotropy Chiroptical studies on anisotropic condensed matter: Principle and recent applications of the generalized-high accuracy universal polarimeter in Crystal Growth and Chirality – Technologies and Applications IntechOpen (2023) Absolute chirality of the γ-polymorph of glycine: Correlation of the absolute structure with the optical rotation A high-accuracy universal polarimeter study of optical anisotropy and optical activity in laminated collagen membranes Optical activity and optical anisotropy in photomechanical crystals of chiral salicylidenephenylethylamines Accurate measurement of the optical activity of alanine crystals and the determination of their absolute chirality Determination of the Faraday rotation perpendicular to the optical axis in uniaxial CeF3 crystal by using the Generalized-High Accuracy Universal Polarimeter Giant optical anisotropy in high temperature superconducting cuprate Bi2Sr2CaCu2O8+δ Imaging the impact on cuprate superconductivity of varying the interatomic distances within individual crystal unit cells High critical-current density in the heavily Pb-doped Bi2Sr2CaCu2O8+δ superconductor: Generation of efficient pinning centers Structural modulation and superconducting properties in Bi2–xPbxSr2CaCu2O8+δ and Bi2–yPbySr2YCu2O8+δ Superconductive transition at 98.5 K in monoclinic (Bi,Pb)2Sr2CaCu2O8 Two-phase microstructures generating efficient pinning centers in the heavily Pb-substituted Bi2Sr2CaCu2O8+δ single crystals Evolution of incommensurate superstructure and electronic structure with Pb substitution in (Bi2–xPbx)Sr2CaCu2O8+δ superconductors Fabrication of multifilamentary powder in tube superconducting tapes of Bi-2223 with Sr deficient starting composition Effect of suspension parameters towards the fabrication of BSCCO films by electrophoretic deposition Structural origin of the low superconducting anisotropy of Bi1.7Pb0.4Sr2Ca0.9Cu2O8 crystals Study on resistivity anisotropy and flux pinning of Bi2–xPbxSr2CaCu2Oy single crystals Effect of Pb doping on the electrical properties of textured Bi-2212 superconductors Structure and bonding of Bi-Sr-Ca-Cu-O crystal by X-ray photoelectron spectroscopy Experimental electronic structure of Bi2CaSr2Cu2O8+δ XPS study of Bi-Sr-Ca-Cu-O superconducting thin films prepared by the rf-sputtering method The fine structure of the Cu2p3/2 X-ray photoelectron spectra of copper oxide based compounds An XPS study of as-grown superconducting Bi-Sr-Ca-Cu-O thin film with Tc0 of 98 K Core-level photoemission study on a Bi-2212 single crystal XPS studies on the superconductor-insulator transition in Bi2–xPbxSr2Ca1–yYyCu2O8+δ system Comparative photoemission studies of Bi2–xPbxSr2Can–1CunO2n+4+y (n = 2 A comparative X-ray photoemission study of Bi2Sr2CaCu2O8+δ and Bi1.6Pb0.4Sr2CaCu2O8+δ Site occupancies of Sr and Ca ions in Bi2(Sr1–xCax)3Cu2Oy studied by photoemission core-level spectroscopy Charge-transfer induced by Pb-doping and annealing in Bi-2212 phase superconductor Pb-substitution effect on the electronic properties of Bi2201 Effects of doping on phonon Raman scattering in the Bi-based 2122 system Study of the influence of hole concentration on high-Tc superconductivity of cuprates Bi-2212 by X-ray photoelectron spectroscopy Structure and physical properties of single crystals of the 84-K superconductor Bi2.2Sr2Ca0.8Cu2O8+δ Superconducting properties of Pb-free and Pb-substituted bulk ceramics of Bi-2212 cuprates Pb introduction to the High-Tc superconductor Bi-Sr-Ca-Cu-O Investigation of (Bi,Pb)Bi2212 crystal: Observation of modulation-free phase Optical activity in the incommensurate phase of ferroelectric {N(CH3)4}2ZnCl4 Optical activity of incommensurate state of [N(CH3)4]2CuCl4 Optical and X-ray studies on incommensurate phase transitions of ferroelectric ammonium fluoroberyllate (NH4)2BeF4 Optical study on incommensurate phase transitions of (C3H7NH3)2MnCl4 Birefringence and optical activity of the incommensurate phase of [N(CH3)4]2ZnCl4 Optical activity and birefringence of the incommensurate phase of Rb2ZnBr4 Optical activity and birefringence of the incommensurate phase of Rb2ZnCl4 p-Type transparent conductivity in high temperature superconducting Bi-2212 thin films Molecular Light Scattering and Optical Activity (Cambridge Univ Physical Properties of Crystals: Their Representation by Tensors and Matrices (Oxford Univ Polar Kerr effect as probe for time-reversal symmetry breaking in unconventional superconductors Download references Nagai (National Institute for Materials Science) Xie Peiao (Tohoku University) for their technical support This study was financially supported by the Mizuho Foundation for the Promotion of Sciences and the Grant for Research Base Creation This work was partially carried out under the Global Institute for Materials Research Tohoku (GIMRT) Program of the Institute for Materials Research These authors contributed equally: Keigo Tokita and Kenta Nakagawa All authors discussed the results and commented on the manuscript Below is the link to the electronic supplementary material Download citation DOI: https://doi.org/10.1038/s41598-024-78208-6 Leading the task force will be Commissioner Hester Peirce dubbed "crypto mom" by many for her support of innovation and evolution in the crypto industry while also opposing a so-called "regulation-by-enforcement" approach previously taken by the Commission under former Chair Gary Gensler In announcing its newly launched task force the SEC described its goals and a new direction for its approach to crypto Commissioners Jaime Lizárraga and Caroline Crenshaw Relying on enforcement actions as the primary means to regulate crypto determined to implicate federal securities laws Aiming for clearer regulation and guidance and "deploy[ing] enforcement resources judiciously" Uncertainty regarding who must register (and how to register) crypto as securities Establishing a practical and achievable process for registration when warranted Confusing legal environment for crypto innovators whose business may implicate federal securities laws Designing clearly defined disclosure requirements and frameworks At the same time, there has been no announcement regarding the state or fate of the SEC Division of Enforcement's Cyber and Crypto Unit (CACU), which was formed in 2017 and which in mid-2022 the agency staffed up with additional attorneys and other internal resources, signaling at the time that expansion was needed to "police wrongdoing in the crypto markets …" we will be watching developments on Capitol Hill With Republicans now in control of both the House Financial Services and Senate Banking committees Congress and the White House are expected to work together on legislation addressing stablecoins and market structure reform further defining the roles of the SEC and CFTC in crypto regulations the White House is working to establish a crypto council to develop new regulatory policies making 2025 an active and exciting year in this space 1 See SEC v 293 (1946) for the so-called Howey test: (i) investment of money (ii) in a common enterprise (iii) with profits to be derived solely from the efforts of others Please note that email communications to the firm through this website do not create an attorney-client relationship between you and the firm Do not send any privileged or confidential information to the firm through this website Click "accept" below to confirm that you have read and understand this notice Stony Brook University Hospital (SBUH) employees have teamed up with a local church to collect much-needed supplies for Ukrainian refugees assistant director of nursing for the Cardiac Care Unit (CCU) and the Cardiac Acute Care Unit (CACU) assistant director of the Neuro Critical Care Unit (NCCU) have been directing a relief drive that is collecting new items requested by St John the Baptist Ukrainian Catholic Church in Riverhead The church is working with a relief organization and shipping company to get the items delivered overseas Members of the Stony Brook community can contribute to the drive through Thursday by donating items at level 5 in the Heart Center in the CCU The items will be delivered to the church on April 1 with the assistance of the courier service at SBUH The drive has been collecting a variety of items: medical supplies like gauze and pain medication; baby items such as diapers and toys; non-perishable foods; tactical gear like flashlights sleeping bags and thermoses; and clothing including socks and looked to start a collection drive similar to the one that students held on West Campus earlier this month She said she has not been surprised by the impressive turnout so far “Our Stony Brook community is always giving to our community one way or another,” Marrone said and website in this browser for the next time I comment 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Stony Brook University marked Veterans Day with a moving ceremony November 11 paying tribute to the sacrifices of military personnel and the presidents of SUNY’s four university centers — University at Albany Stony Brook University has launched an eco-friendly remote-controlled craft that will gathering vital biodiversity data in Shinnecock Bay © 2024 Stony Brook University Woba woshima gusoma iki kiganiro muri uru rurimi: %% Yezu ni inzira, ikig. 101 Yezu ni inzira, ikig. 102 Yezu ni inzira, ikig. 103-104 Yezu ni inzira, ikig. 105-114 Yezu ni inzira, ikig. 115 Yezu ni inzira, ikig. 116-126 Yezu ni inzira, ikig. 127-133 Yezu ni inzira, ikig. 134-135 Metrics details An Author Correction to this article was published on 03 April 2019 This article has been updated Dopants and impurities are crucial in shaping the ground state of host materials: semiconducting technology is based on their ability to donate or trap electrons and they can even be used to transform insulators into high temperature superconductors most atomic-scale studies of the latter materials focussed on the effect of dopants on the electronic properties averaged over time by using atomic-scale current-noise measurements in optimally doped Bi2Sr2CaCu2O8+x we visualize sub-nanometre sized objects where the tunnelling current-noise is enhanced by at least an order of magnitude We show that these objects are previously undetected oxygen dopants whose ionization and local environment leads to unconventional charge dynamics resulting in correlated tunnelling events The ionization of these dopants opens up new routes to dynamically control doping at the atomic scale enabling the direct visualization of local charging on e.g the study of charged defects and their dynamics has mostly concentrated on semiconductor materials many correlated electron systems show a rich phase diagram as a function of impurity doping Doped materials such as the high temperature superconducting cuprates and related ruthenates whose parent compounds are Mott insulators are particularly interesting in this regard as the dopant atoms often reside in otherwise insulating layers—a promising environment for charge dynamics to occur these sites would open up a new avenue to study the effect of impurities on the physical properties of the system to our knowledge no reports have been made of local dynamic charging effects in any of these systems which seems to indicate that despite the insulating nature of the layers where the dopant atoms reside the coupling of the dopants to the continuum conduction or valence bands is still too strong for charging to affect tunnelling on the millisecond time-scales that can typically be addressed with an STM equipped with our shot-noise-enabled scanning tunnelling microscope we set out to look for signatures of charging at atomic-scale defects on time-scales on the order of the tunnelling process in the near-optimally doped high temperature superconductor Bi2Sr2CaCu2O8+x (Bi2212) We immediately visualize sub-nanometre-sized objects where the tunnelling current noise is enhanced by at least an order of magnitude we argue that these objects are oxygen dopant atoms that were unaccounted for in previous scanning probe studies whose local environment leads to charge dynamics that strongly affect the tunnelling mechanism can be up to tens of times higher than for the random tunnelling seen at low energies General characteristics of noisy defects. a Average current-noise image constructed from 44 defects in Fig. 1d b Average topographic image corresponding to (a) The clear atomic contrast indicates that the defects are all located at roughly the same location c Typical differential conductance spectrum plotted versus the current (solid red the dip is located at E = −0.75 eV) and simultaneously recorded noise (blue markers and line right axis): the drop in differential conductance is strongly correlated with the deviation of the noise from Poissonian (dashed line) F = 1) is strongly correlated with the drop in differential conductance Negative differential conductance and dispersion a Constant current image of an area with a noisy defect (E = −100 meV b–f Spatially resolved current-noise for five different energies: the noise initially appears (in (c)) on top of four neighbouring Bi atoms then radially moves outwards for increasing energies (each energy is recorded at Isetup = 400 pA) Blue dots mark the location of the Bi atoms in (a) g Differential conductance taken on the Bi atom marked in (a) for increasing setup currents (Esetup = −1 eV) h Current-noise recorded simultaneously with (g) Poissonian (SI = 2eI) and quadratic dependence of the noise on current (SI = A2eI2 A = 3.4 × 1010) are indicated with dotted lines Weak coupling to the CuO2 plane of some defects due to their local environment leads to charging and de-charging that modulates the current through the main conduction channels—for the bottom defect in (a) this is through the four neighbouring Bi atoms as indicated by the thick dashed arrows Additional studies on even larger fields of view may provide sufficient statistics for such an analysis we have evidence that this is indeed the case the noise power spectral density we measure is the sum of the shot-noise and the thermal noise local (energy-dependent) heating could therefore enhance the total current-noise to reach noise levels we observe on a number of defects would require local electron temperatures of >20 K which is highly unlikely for our sample temperature of <2 K by combining STM and current-noise measurements we resolve atomic-scale defects where the current-noise is strongly enhanced and the differential conductance reduced—for some defects even negative These noisy defects most likely constitute a subset of the oxygen dopant atoms that are introduced to turn the Mott insulator Bi2212 into a high temperature superconductor dopants that were unaccounted for in previous scanning probe studies The locally enhanced current-noise and reduced differential conductance is expected for charging and de-charging on short time-scales $\left( { \ll \,{\mathrm{ms}}} \right)$ due to weak coupling of these dopants to the CuO2 charge reservoir resulting in local potential fluctuations that strongly affect the dominant tunnelling channel(s) the exact details of the local environment plays a key role in the charge dynamics of oxygen dopants and their effect on the tunnelling process can in principle be utilised to dynamically control the doping at the atomic scale finite frequency stroboscopic techniques will be required as the charging and de-charging time-scale is relatively short Such experiments will enable the direct visualization of the effect of locally changing the charge providing novel microscopic insight into the origin of the various broken symmetry phases and high-Tc superconductivity observed in the cuprates The Fano factor (F) plotted throughout this work is defined as the slope of the current-noise vs For the locations with excess current-noise where the current-noise is quadratically dependent on the current the Fano factor at a given current (I0) is what would have been the slope had the current-noise at I0 ≤ I ≤ 0 obeyed a linear current dependence A bandpass filter followed by a Herotek DZM020BB diode was used to integrate the noise amplitude spectral density in the 100 kHz to 5 MHz frequency range Lock-in measurements of the noise at the LCcable resonance of 1 MHz gave identical results All presented measurements were recorded at T = 1.8 K The data that support the findings of this study are available from the corresponding author upon reasonable request The original version of this Article contained an error in the right-hand y-axis of Fig The correct version states ‘nA’ in place of ‘pA’ This has been corrected in both the PDF and HTML versions of the Article 1/f and random telegraph noise in silicon metal-oxide semiconductor field-effect transistors Large on–off ratios and negative differential resistance in a molecular electronic device Identification of atomic-like electronic states in indium arsenide nanocrystal quantum dots Atomic scale conductance induced by single impurity charging Bistability in atomic-scale antiferromagnets Imaging the dynamics of individually adsorbed molecules Suppression of electron–vibron coupling in graphene nanoribbons contacted via a single atom Tuning charge and correlation effects for a single molecule on a graphene device Controlling the charge state of individual gold atoms Tunable control over the ionization state of single Mn acceptors in GaAs with defect-induced band bending Controlled charge switching on a single donor with a scanning tunneling microscope Effect of charge manipulation on scanning tunneling spectra of single Mn acceptors in InAs Time-resolved single dopant charge dynamics in silicon Recent advances in studies of current noise In CFN Lectures on Functional Nanostructures—Volume 2 Atomic scale shot-noise using cryogenic MHz circuitry Amplifier for scanning tunneling microscopy at MHz frequencies Impurity states and interlayer tunneling in high temperature superconductors Local electronic structure of Bi2Sr2CaCu2O8 near oxygen dopants Correlating off-stoichiometric doping and nanoscale electronic inhomogeneity in the high-Tc superconductor Bi2Sr2CaCu2O8+δ Spectral decomposition and matrix element effects in scanning tunneling spectroscopy of Bi2Sr2CaCu2O8+δ Origin of the electron–hole asymmetry in the scanning tunneling spectrum of the high-temperature Bi2Sr2CaCu2O8+δ superconductor Nanoscale interplay of strain and doping in a high-temperature superconductor Interpretation of scanning tunneling quasiparticle interference and impurity states in cuprates Observations of electronic inhomogeneity in heavily pb-doped Bi2Sr2CaCu2Oy single crystals by scanning tunneling microscopy Direct determination of localized impurity levels located in the blocking layers of Bi2Sr2CaCu2Oy using scanning tunneling microscopy/spectroscopy Atomic-scale sources and mechanism of nanoscale electronic disorder in Bi2Sr2CaCu2O8+δ Imaging the impact of single oxygen atoms on superconducting Bi2+ySr2−yCaCu2O8+x Electronic band structure of CaBi2Sr2Cu2O8 Valence-band states in Bi2(Ca,Sr,La)3Cu2O8 Tunneling spectroscopy of the GaAs(110) surface Metallic in-plane and divergent out-of-plane resistivity of a high-Tc cuprate in the zero-temperature limit Metallic supercurrent field-effect transistor Analytic model of shot noise in double-barrier resonant-tunneling diodes Shot noise in double barrier quantum structures Enhanced shot noise in resonant tunneling: theory and experiment Shot noise enhancement in resonant-tunneling structures in a magnetic field Transition from sub-Poissonian to super-Poissonian shot noise in resonant quantum wells Enhanced shot noise in resonant tunneling via interacting localized states and relaxation effects in transport through molecules Super-Poissonian shot noise in the resonant tunneling due to coupling with a localized level Electron bunching in transport through quantum dots in a high magnetic field Noise characteristics of charge tunneling via localised states in metal–molecule–metal junctions Negative differential conductance and super-Poissonian shot noise in single-molecule magnet junctions Download references would like to acknowledge funding from H2020 Marie Skłodowska-Curie Actions (Grant number 659247) and the ANR (ANR-16-ACHN-0018-01) Laboratoire de Physique des Solides (CNRS UMR 8502) Université Paris-Sud/Université Paris-Saclay Journal peer review information: Nature Communications thanks the anonymous reviewers for their contribution to the peer review of this work Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations Reprints and permissions Download citation DOI: https://doi.org/10.1038/s41467-019-08518-1 Metrics details superconductivity is accompanied by a plethora of orders and phenomena that complicate our understanding of superconductivity in these materials these orders weaken or vanish with overdoping we approach the superconducting phase from the more conventional overdoped side We present angle-resolved photoemission spectroscopy studies of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta }$ cleaved and annealed in ozone to increase the doping all the way to the non-superconducting phase We show that the mass renormalization in the antinodal region of the Fermi surface that possibly reflects the pairing weakens with doping and completely disappears precisely where superconductivity disappears This is the evidence that in the overdoped regime superconductivity is determined primarily by the coupling strength A doping dependence and an abrupt disappearance above the transition temperature eliminate phononic mechanism of the observed renormalization and identify the onset of spin-fluctuations as its likely origin The effects of strong correlations extend far away from half filling deep into the regime that overlaps with superconductivity where their presence and intertwining with superconductivity complicates the identification of the superconducting mechanism it would be desirable to study superconducting properties in the highly overdoped regime where such effects are absent or strongly reduced this has made it possible to monitor the development of electronic excitations as superconductivity weakens and finally completely disappears we perform ARPES studies in the overdoped regime of Bi2212 and discover the mass renormalization of antinodal electrons that indicates a coupling to some bosonic-like mode The coupling correlates strongly with superconductivity It weakens with doping and vanishes at the point where superconductivity disappears The doping and temperature dependences eliminate phononic mechanism of the observed renormalization and identify the onset of spin-fluctuations as its likely origin a Phase diagram near the edge of the superconducting dome, as determined from ref. 12 ${T}_{{\rm{c}}}$ and Δ0 for the doping levels from this study are indicated by the black and red solid squares b Fermi surface ($E=0$ contour) of the overdoped corresponding to $p=0.29$ and c of the ${T}_{{\rm{c}}}=72$ K sample (horizontal error bars in a) is approximated to be proportional to the width of the Fermi surface: $\Delta p/p \sim 2\Delta {k}_{{\rm{F}}}/{k}_{{\rm{F}}}$ The uncertainty in ${T}_{{\rm{c}}}$ is given by the temperature step size in $T$-dependent ARPES measurements that identify ${T}_{{\rm{c}}}$ The uncertainty in gap magnitude corresponds to the standard deviation of the quasiparticle peak position determined from fitting that shows no superconductivity within our detection limits the Van Hove singularity of the antibonding state sits exactly at the Fermi level The uncertainty in $\lambda$ in b and d is the standard deviation of the slope obtained from the linear fit of low-energy Re$\Sigma$ The uncertainty in ${\Omega }_{0}$ in c corresponds to the standard deviation of the peak position in Re$\Sigma$ determined from fitting except for the as-grown sample (see the Methods section) We note that a weak featureless renormalization remains at $p=0.29$ and in the normal state of superconducting samples That component does not display any doping dependence in the studied range We call the corresponding slope of Re$\Sigma$ the critical coupling ${\lambda }_{{\rm{c}}}$ as the $p=0.29$ sample sits exactly at the superconducting boundary kink should be present in both the normal and superconducting states It would also explain a large disparity in ${T}_{{\rm{c}}}$ in these two families of cuprates This is a good news and an indication that ${T}_{{\rm{c}}}$ in cuprates does not have a natural limit in the coupling strength itself there are many phenomena that limit ${T}_{{\rm{c}}}$ some of these probably being caused by the strong coupling observed here The point corresponding to the ${T}_{{\rm{c}}}=91$ K sample indicates that this region might already be affected The starting sample was a slightly overdoped (${T}_{{\rm{c}}}=91$ K) single-crystal of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta }$ synthesized by the traveling floating zone method It was clamped to the sample holder and cleaved with Kapton tape in the ARPES preparation chamber (base pressure of $3\times 1{0}^{-8}$ Pa) as well as the need for its processing at elevated temperatures resulting in perfectly flat cleaved surfaces and unaltered doping level The cleaved sample was then transfered to the MBE chamber (base pressure of $8\times 1{0}^{-8}$ Pa) where it was annealed in $3\times 1{0}^{-3}$ Pa of cryogenically distilled O$_{3}$ at 350–480 °C for $\approx$1 h sample was cooled to room temperature in the ozone atmosphere and transfered to the ARPES chamber (base pressure of $8\times 1{0}^{-9}$ Pa) No spectral gap was detected down to the base temperature (12 K) and the doping level determined from the area of the Fermi surface was $p=0.29$ Reduction in doping was achieved by subsequent annealing of the same surface in vacuum to temperatures ranging from 110 to 175 °C resulting in development of superconductivity with increasing ${T}_{{\rm{c}}}$ The ARPES experiments were carried out on a Scienta SES-R4000 electron spectrometer with the monochromatized HeI (21.22 eV) radiation (VUV-5k) The total instrumental energy resolution was $\sim$4 meV Angular resolution was better than ${\sim} 0.1{5}^{\circ }$ and $0.{3}^{\circ }$ along and perpendicular to the slit of the analyzer The ARPES estimate of ${T}_{{\rm{c}}}$ was within $\pm \ except for the sample falling outside of the superconducting dome for which the estimate was limited by the base temperature that could be reached with our cryostat (\({T}_{{\rm{c}}}\ <\ 12$ K) a Electronic structure near the antinode along the momentum line indicated in Fig. 1b at low temperature ($T \sim 12$ K) for the as-grown Bi2212 sample The MDC-fitted dispersions of the bonding state is indicated by the blue curve The TB dispersion is indicated by the solid red curve The dashed red curve represents the TB dispersion gapped by ${\Delta }_{0}=34$ meV b The energy distribution curves corresponding to the ${k}_{{\rm{F}}}$ (black) and the momentum indicated by the red vertical arrow in a The horizontal black arrow indicates the dip in the intensity The bare in-plane band structure of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta }$ is approximated by the tight-binding formula: where the index A (B) is for antibonding (bonding) state and $\mu$ is chemical potential The hopping parameters that best describe the Fermi surfaces of the measured samples are kept fixed at $t=0.36$ with only the chemical potential being varied from 0.467 eV for the non-superconducting sample to 0.425 eV The TB contours that agree with the experimental contours the best were chosen by eye By changing them to the point where discrepancies would become clearly visible we can estimate that the uncertainty in doping of this method is very close to that estimated from the experimental momentum width of the Fermi surface $\Delta p/p \sim 2\Delta {k}_{{\rm{F}}}/{k}_{{\rm{F}}}$ the kink is significantly deeper than the renormalized bottom of the antibonding band the effect should not disappear in the normal state Another candidate that could possibly have similar effects on the measured quasiparticle dispersion and its lifetime is the superconducting gap itself The observed ${\Omega }_{0}$ is very close to ${\Delta }_{0}$ and the reduction of a phase space for scattering related to the opening of the gap would make the states sharp within a certain energy range with details depending on the gap symmetry measured from the top of quasiparticle dispersion ${\Delta }_{0}$) This might not be strictly valid for the $d$-wave gap where the scattering could involve the node-antinode mixing the strength of the antinodal kink weakens rapidly as one moves from the antinode implying that the mode scatters antinode to the antinode the mode’s momentum has to be either $Q\approx 0$ effectively excluding the node to antinode mixing and the pair-breaking as its origin The data that support the findings of this study are available from the corresponding author upon reasonable request. The source data underlying Figs. 1a and 3b–d are provided as a Source Data file Lead phonon spectrum calculated from superconducting density of states Evidence for quantum critical behavior in the optimally doped cuprate Bi2Sr2CaCu2O8+ Bosons in high-temperature superconductors: an experimental survey Broken relationship between superconducting pairing interaction and electronic dispersion kinks in La2xSrxCuO4 measured by angle-resolved photoemission Coherent organization of electronic correlations as a mechanism to enhance and stabilize high-T C cuprate superconductivity Rapid change of superconductivity and electron-phonon coupling through critical doping in Bi-2212 Doping a Mott insulator: physics of high-temperature superconductivity Anisotropic electron-phonon coupling and dynamical nesting on the graphene sheets in superconducting cac6 using angle-resolved photoemission spectroscopy Quantitative determination of pairing interactions for high-temperature superconductivity in cuprates Resonant spin excitation in an overdoped high temperature superconductor Low-energy antiferromagnetic spin fluctuations limit the coherent superconducting gap in cuprates Physical origin of the buckling in CuO2 : electron-phonon coupling and Raman spectra Dependence of the critical temperature in overdoped copper oxides on superfluid density Evidence for ubiquitous strong electron-phonon coupling in high-temperature superconductors Doping dependence of low-energy quasiparticle excitations in superconducting Bi2212 A relation between the resonance neutron peak and ARPES data in cuprates Dispersion anomalies in cuprate superconductors Effect of an electron-phonon interaction on the one-electron spectral weight of a d-wave superconductor Novel neutron resonance mode in dx2-y2-wave superconductors Strength of the spin-fluctuation-mediated pairing interaction in a high-temperature superconductor Dependence of T c on the q $\omega$ structure of the spin-fluctuation spectrum Direct observation of a magnetic gap in superconducting La 1.85 Sr 0.15 CuO 4 (T c = 37.3 K) Hidden quantum spin-gap state in the static stripe phase of high-temperature La2xSrxCuO4 superconductors The ground state of the pseudogap in cuprate superconductors Coexistence of a pseudogap and a superconducting gap for the high T c superconductor La2xSrxCuO4 studied by angle-resolved photoemission spectroscopy C.K. Kim, et al. In-situ angle-resolved photoemission spectroscopy of copper-oxide thin films synthesized by molecular beam epitaxy. J. Electron Spectrosc. Relat. Phenom. https://doi.org/10.1016/j.elspec.2018.07.003 (2018) Angle-resolved photoemission studies of the cuprate superconductors Point nodes persisting far beyond Tc in Bi2212 Download references This work was supported by the US Department of Energy Condensed Matter Physics and Materials Science Department made contributions to development of the OASIS facility used herein and commented on the manuscript Peer review information Nature Communications thanks the anonymous reviewers for their contribution to the peer review of this work Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations Download citation DOI: https://doi.org/10.1038/s41467-020-14282-4 Metrics details Establishing the presence and the nature of a quantum critical point in their phase diagram is a central enigma of the high-temperature superconducting cuprates It could explain their pseudogap and strange metal phases and ultimately their high superconducting temperatures while solid evidences exist in several unconventional superconductors of ubiquitous critical fluctuations associated to a quantum critical point in the cuprates they remain undetected until now Here using symmetry-resolved electronic Raman scattering in the cuprate ${\mathrm{Bi}}_2{\mathrm{Sr}}_2{\mathrm{CaCu}}_2{\mathrm{O}}_{8+\delta}$ we report the observation of enhanced electronic nematic fluctuations near the endpoint of the pseudogap phase While our data hint at the possible presence of an incipient nematic quantum critical point the doping dependence of the nematic fluctuations deviates significantly from a canonical quantum critical scenario The observed nematic instability rather appears to be tied to the presence of a van Hove singularity in the band structure Dynamical nematic fluctuations in ${\mathrm{Bi}}_2{\mathrm{Sr}}_2{\mathrm{CaCu}}_2{\mathrm{O}}_{8+\delta}$ a Temperature-doping generic phase diagram of hole-doped cuprates The pseudogap phase ends at a putative quantum critical point (QCP) located at the doping ${p}^{* }$ b Nematic order breaking the ${{\mathrm{C}}}_{4}$ rotational symmetry of the Cu square lattice down to ${{\mathrm{C}}}_{2}$ symmetry The corresponding order parameter has ${B}_{1g}$ symmetry: in reciprocal space it transforms as ${k}_{x}^{2}$ − ${k}_{y}^{2}$ and switches sign upon 90 degrees rotation x $\to$ y (color scale is defined as blue: negative values c Temperature dependence of the ${B}_{1g}$ Raman spectrum in the normal state for several doping levels in ${\mathrm{Bi}}_{2}{\mathrm{{Sr}}}_{2}{\mathrm{CaCu}}_{2}{{\mathrm{O}}}_{8+\delta }$ The ${B}_{1g}$ symmetry is obtained using cross-photon polarizations at 45 degrees of the Cu–O–Cu direction (see insets) The nature of the ordered state associated to this putative QCP is however not yet settled and nematicity stands as a potential candidate To assess its relevance and the role of nematic degrees of freedom in driving the PG order probing the associated fluctuations is thus essential In the former case nematicity develops along the diagonal of the ${{\mathrm{CuO}}}_{2}$ plane and thus transforms as the ${B}_{2g}$ (or $xy$) symmetry The ability of Raman scattering to resolve the symmetry of the associated order parameter is therefore crucial At these dopings a relatively wide temperature range is accessible above both ${T}^{*}$ and ${T}_{c}$ to probe these fluctuations and look for fingerprints of a nematic QCP The polarization resolved Raman experiments were performed in several configurations of in-plane incoming and outgoing photon polarizations in order to extract the relevant irreducible representations of the ${D}_{4h}$ group: ${B}_{1g}$ which transforms as ${x}^{2}$ − ${y}^{2},{B}_{2g}$ ($xy$) and ${A}_{1g}$ As indicated above while the former two correspond to nematic orders along and at 45 degrees of the Cu–O–Cu bonds the latter one is fully symmetric and is not associated to any symmetry breaking The recorded spectra were corrected by the Bose factor and are thus proportional to the imaginary part of the frequency dependent Raman response function ${\chi}_{\mu}^{\prime\prime}(\omega)$ in the corresponding symmetry ${\mu}$ where ${\mu}$ = ${B}_{1g},{B}_{2g},{A}_{1g}$ (see Methods section for more details on the Raman scattering set-up and polarization configurations) To analyze the observed temperature dependence and its link to a nematic instability it is useful to extract the symmetry resolved static susceptibility ${\chi }_{\mu }(\omega \ =\ 0)$ = ${\chi }_{\mu }^{0}$ from the measured finite frequency response ${\chi}_{\mu}^{\prime\prime}(\omega)$ using Kramers-Kronig relations: b Curie-Weiss fits of the inverse ${B}_{1g}$ nematic susceptibility for temperatures above max(${T}_{c}\,{T}^{*}$) The inset shows the full temperature dependence of the inverse susceptibility of OD74 and UD85 where deviation from Curie-Weiss law are observed at ${T}^{* }$ and an additional upturn is observed at ${T}_{c}$ Full and open symbol correspond to data above and below ${T}^{*}$ Further insight into the doping dependence of these critical nematic fluctuations can be gained by fitting the B${}_{1g}$ static nematic susceptibility using a Curie-Weiss law: we restrict our fits to temperatures above ${T}^{* }$ for doping levels below ${p}^{* }$ and above ${T}_{c}$ for doping level above $p$* the mean-field nematic transition temperature which quantifies the strength of the nematic instability: graphically ${T}_{0}$ corresponds to the zero temperature intercept of the inverse susceptibility Phase diagram of critical nematic fluctuations Color-coded plot summarizing the evolution of the ${B}_{1g}$ nematic susceptibility as a function of doping and temperature in Bi2212 The nematic Curie-Weiss temperature ${T}_{0}$ is also shown along with the superconducting ${T}_{c}$ and pseudogap ${T}^{* }$ temperatures The error bars for ${T}_{0}$ correspond to the standard error of the Curie-Weiss fits The inset shows the Fermi surface deformation associated to the incipient Pomeranchuk instability which breaks the ${C}_{4}$ symmetry are needed in order to clarify the nature of this link and confirm the connection between the nematic instability and the presence of a vHs Raman experiments have been carried out using a triple grating JY-T64000 spectrometer in subtractive mode using two 1800 grooves/mm gratings in the pre-monochromator stage and 600 grooves/mm or 1800 groove/mm grating in the spectrograph stage The 600 grooves/mm grating was used for all measurements except those carried on the OD80 sample for which a 1800 grooves/mm grating was used both configurations were used at selected temperatures to check for consistency The 600 grooves/mm configuration allows us to cover the low-energy part of the spectrum down to 50 cm−1 and up to 900 cm−1 in a single frame measurements could be performed down to 15 cm−1 but spectra must then be obtained in two frames The resolution is set at 5 cm−1 when using the 600 grooves/mm configuration The spectrometer is equipped with a nitrogen cooled back illuminated CCD detector We use the 532 nm excitation line from a diode pump solid state laser Measurements between 10 and 300 K have been performed using an ARS closed-cycle He cryostat All the raw spectra have been corrected for the Bose factor and the instrumental spectral response They are thus proportional to the imaginary part of the Raman response function $\chi ^{\prime\prime} (\omega ,T)$ A potential concern when correcting the raw spectra with the Bose factor is the potential presence of non-Raman signal in the raw spectra To assess this potential non-Raman signal we note that a single effective spot temperature was able to reproduce the measured Stokes spectrum from the anti-Stokes spectrum between 20 and 600 ${{\mathrm{cm}}}^{-1}$ at room temperature In addition the raw Raman spectra were found to extrapolate very close to zero at zero Raman shift at the lowest temperatures measured Both facts indicates negligible non-Raman background in the measured spectra All data generated or analyzed during this study are included in the published manuscript and the supplementary information files. The relevant raw data file are available at the following url: https://doi.org/10.6084/m9.figshare.9906275.v1 Fermi-liquid instabilities at magnetic quantum phase transitions Quantum critical point lying beneath the superconducting dome in iron-pnictides Pairing instability near a lattice-influenced nematic quantum critical point Scattering and pairing in High-T${}_{c}$ cuprates Quantum-critical fluctuations in 2D metals: strange metals and superconductivity in antiferromagnets and in cuprates Local-moment fluctuations in the optimally doped high-Tc superconductor YBa${}_{2}$ Cu${}_{3}$ O${}_{6+\delta}$ Dynamical charge density fluctuations pervading the phase diagram of a Cu-based high-Tc superconductor Magnetic order in the Pseudogap phase of high-Tc superconductors Electrical resistivity anisotropy from self-organized one dimensionality in high-temperature superconductors Electronic liquid crystal state in the high-temperature superconductor YBa${}_{2}$ Cu${}_{3}$ O${}_{6+\delta}$ Intra-unit-cell electronic nematicity of the high-Tc copper-oxide pseudogap states Broken rotational symmetry in the pseudogap phase of a high-Tc superconductor Nematic fermi fluids in condensed matter physics Thermodynamic evidence for a nematic phase transition at the onset of the pseudogap in YBa${}_{2}$ Cu${}_{3}$ O${}_{6+\delta}$ Thermodynamic signatures of quantum criticality in cuprate superconductors Charge nematixity and electronic Raman scattering in Iron-based superconductors Observation of incipient charge nematicity in Ba(Fe${}_{1-x}$ Co${}_{x}$ As)${}_{2}$ single crystals Critical quadrupole fluctuations and collective modes in iron pnictide superconductors Two types of nematicity in the phase diagram of the cuprate superconductor YBa${}_{2}$ Cu${}_{3}$ O${}_{6+\delta}$ Nematicity in stripe-ordered cuprates probed via resonant x-ray scattering Diagonal nematicity in the Pseudogap phase of HgBa${}_{2}$ CuO${}_{4+\delta}$ Spontaneous breaking of rotational symmetry in copper oxide superconductors Collapse of the normal-state Pseudogap at a lifshitz transition in the Bi${}_{2}$ Sr${}_{2}$ CaCu${}_{2}$ O${}_{8+\delta}$ cuprate superconductor Pseudogap behavior in single-crystal Bi${}_{2}$ Sr${}_{2}$ CaCu${}_{2}$ O${}_{8+\delta}$ probed by ${Cu}$ NMR Strong pairing interactions in the underdoped region of Bi${}_{2}$ Sr${}_{2}$ CaCu${}_{2}$ O${}_{8+\delta}$ Energy gap evolution in the tunneling spectra of Bi${}_{2}$ Sr${}_{2}$ CaCu${}_{2}$ O${}_{8+\delta}$ Phase competition in trisected superconducting dome Doping dependencies of onset temperatures for the Pseudogap and superconductive fluctuation in Bi${}_{2}$ Sr${}_{2}$ CaCu${}_{2}$ O${}_{8+\delta}$ studied from both in-plane and out-of-plane magnetoresistance measurements Direct spectroscopic evidence for phase competition between the pseudogap and superconductivity in Bi${}_{2}$ Sr${}_{2}$ CaCu${}_{2}$ O${}_{8+\delta}$ Raman and ARPES combined study on the connection between the existence of the pseudogap and the topology of the Fermi surface in Bi${}_{2}$ Sr${}_{2}$ CaCu${}_{2}$ O${}_{8+\delta}$ Observation of an unconventional metal-insulator transition in overdoped CuO${}_{2}$ compounds Characterization of the intra-unit-cell magnetic order in Bi${}_{2}$ Sr${}_{2}$ CaCu${}_{2}$ O${}_{8+\delta}$ Lattice effects on nematic quantum criticality in metals Xie, T. et al. Spontaneous nematic transition within the pseudogap state in cuprates. Preprint at https://arxiv.org/abs/1805.00666 (2018) Ishida, Y. et al. Divergent nematic susceptibility near the pseudogap critical point in a cuprate superconductor. Preprint at https://arxiv.org/abs/1908.07167 (2019) Electronic liquid-crystal phases of a doped Mott insulator Instability toward formation of quasi-one-dimensional fermi surface in two-dimensional t-J model d-Wave Superconductivity and Pomeranchuk Instability in the Two-Dimensional Hubbard Model Spatially modulated electronic nematicity in the three-band model of cuprate superconductors Formation of an electronic nematic phase in interacting fermion systems Mean-field theory for symmetry-breaking Fermi surface deformation on a square lattice & Fradkin Quantum theory of a nematic Fermi fluid Soft fermi surfaces and breakdown of Fermi-liquid behavior Divergent nematic susceptibility in an iron arsenide superconductor Nematic quantum critical point without magnetism in FeSe${}_{1-x}$ S${}_{x}$ superconductors Pseudogap and fermi-surface topology in the two-dimensional Hubbard model Correlation-driven Lifshitz transition at the emergence of the Pseudogap Phase in the two-dimensional Hubbard model Heat transport in a strongly overdoped cuprate: Fermi Liquid and a Pure d-Wave BCS Superconductor Fermi surface and quasiparticle excitations of overdoped Tl${}_{2}$ Ba${}_{2}$ CuO${}_{6+\delta}$ The doping dependence of T*-what is the real high-Tc phase diagram Loss of nodal quasiparticle integrity in underdoped YBa${}_{2}$ Cu${}_{3}$ O${}_{6+\delta}$ Download references The work at Brookhaven National Laboratory was supported by the Office of Science performed the Raman scattering experiments with the help of M.C. performed the data analysis and prepared the figures grew the single crystals and the annealing procedure to obtain underdoped and overdoped compositions performed the high-pressure annealing of the crystals for the strongly overdoped compositions wrote the paper with inputs from all the authors Peer review information Nature Communications thanks Bruce Gaulin and the other reviewer(s) for their contribution to the peer review of this work Download citation DOI: https://doi.org/10.1038/s41467-019-12940-w Metrics details the doping of carriers into the parent Mott insulator induces superconductivity and various other phases whose characteristic temperatures are typically plotted versus the doping level p p cannot be determined from the chemical composition but it is derived from the superconducting transition temperature using the assumption that the Tc dependence on doping is universal we present angle-resolved photoemission studies of Bi2Sr2CaCu2O8+δ cleaved and annealed in vacuum or in ozone to reduce or increase the doping from the initial value corresponding to Tc = 91 K We show that p can be determined from the underlying Fermi surfaces and that in-situ annealing allows mapping of a wide doping regime covering the superconducting dome and the non-superconducting phase on the overdoped side Our results show a surprisingly smooth dependence of the inferred Fermi surface with doping the superconducting gap approaches the value of 2Δ0 = (4 ± 1)kBTc we revisit the Bi2212 phase diagram by modifying the doping level of the as-grown crystal by annealing in situ cleaved samples either in vacuum resulting in overdoping of the near-surface region We were able to span a wide region of the phase diagram where the superconductivity was completely suppressed (OD0) we were able to infer the doping level directly from ARPES by measuring the volume of the underlying FS we follow the development of spectral features with doping with unprecedented clarity and detail and construct the phase diagram of Bi2212 Development of the electronic structure of Bi2Sr2CaCu2O8+δ at the Fermi level with doping obtained by annealing of the as grown samples in vacuum obtained by annealing of as grown samples in O3 is integrated within ±2.5 meV around the Fermi level Solid (dashed) lines represent the bonding (antibonding) states obtained from the tight-binding approximation that best fits the experimental data The fitting involved the lines connecting the experimental minimal gap loci in all cases where the underlaying Fermi surface was gapped e Dispersion of states along the red dashed line in a B′) were approximated by the points where the dispersion acquire maximum d Intensity contour for sample UD85 (from c) at E = −20 meV and h E = −40 meV The area enclosed by the TB lines that best represent the experimental data is calculated and used for determination of the doping parameter pA The superconducting transition temperature is determined from magnetic susceptibility measurements (as grown and underdoped samples) and from ARPES data In all samples studied here in the SC phase QPs retain coherence on both sides of this boundary further theoretical and experimental studies will be required Spectral gap from the anti-nodal region of Bi2Sr2CaCu2O8+δ with the dashed red line indicating the momentum line that is probed in b–e for samples with different oxygen content b–e ARPES intensity as a function of binding energy and momentum along the dashed line in a f The EDC curves taken at the Fermi wave-vector of the bonding state from the anti-nodal region of the Fermi surface g Temperature dependence of ARPES spectra for the underdoped sample (Tc = 78 K) and h for the overdoped sample The spectra in g and h are taken at kF marked with red and black dots in a h are symmetrized relative to the Fermi level j Temperature dependence of several spectral parameters for the two samples shown in g h: intensity at the Fermi level (black triangles) and at the peak energy (blue squares) Leading edge gap (LEG) of non-symmetrized spectra (red circles) and apparent quasiparticle peak position (gray diamonds) The error bars in j correspond to the fitting uncertainties in the apparent quasiparticle peak positions from h The shaded area marks the region that has not been studied before Characteristic temperatures are displayed against the left axis while the right axis is for the spectral gap b Ratio of the antinodal gap and Tc for the points shown in a from the overdoped side The red dashed line corresponds to the BCS value for d-wave gap We have approximated the uncertainty in doping (horizontal error bars in a) to be proportional to the width of the Fermi surface: ΔpA/pA ~ 2ΔkF/kF The uncertainty in Tc is given by the width of superconducting transition in susceptibility measurements (underdoped samples) or by the temperature step size in T-dependent ARPES measurements that identify Tc (overdoped samples) The uncertainty in gap magnitude (red vertical error bars in a) corresponds to the standard deviation of the quasiparticle peak position determined from fitting It serves to determine the propagated uncertainty (vertical error bars) in b shows much more drastic departure from the universal SC dome with the maximal Tc occurring near pA = 0.3 the Lifshitz transition affects only one FS and not the other This would suggest that the changes in the antibonding state are for some reason more important for superconductivity than those in the bonding state it is not clear why this should be the case One suggestion could be that the straight segments of the bonding states FS are susceptible to nesting and are involved in charge the lack of a gap and other effects that these phenomena should induce into the spectral response certainly argues against this scenario it seems that the curvature (or a lack of it) of the FS in the antinodal region plays a significant role in cuprate superconductivity and that the straight antinodal segments of the FS might be ineffective in forming the efficient singlet pairs even when not contributing to density waves This might be because the group velocity of these straight segments lacks the component that would connect them from kF to −kF into singlet pairs Further studies on other multi-layered cuprate superconductors will be necessary to resolve these questions The starting samples were slightly overdoped (Tc = 91 K) single-crystals of Bi2212 They were clamped to the sample holder and cleaved with Kapton tape in the ARPES preparation chamber (base pressure of 3 × 10−8 Pa) commonly used for mounting samples and associated processing at elevated temperatures The cleaved samples were then annealed in situ in the ARPES preparation chamber to different temperatures ranging from 150 to 700 °C for several hours resulting in the loss of oxygen and underdoping the cleaved as-grown samples were transfered to the MBE chamber (base pressure of 8 × 10−8 Pa) where they were annealed in 3 × 10−3 Pa of cryogenically distilled O3 at 350–480 °C for ≈1 h films were cooled to room temperature in the ozone atmosphere and transfered to the ARPES chamber (base pressure of 8 × 10−9 Pa Vacuum annealing results in generally homogeneous doping profile where the surface Tc measured by ARPES shows no variation with repeated re-cleaving of the annealed crystals and is in a good agreement with the bulk susceptibility measurements Annealing of as grown crystals in O3 results in increased doping in the near-surface region reduced spectral gap and its closing temperature The most of the crystals volume remained near the optimal doping upon ozone annealing The thickness of the overdoped surface layer was in the sub-micron range semi-transparent re-cleaved flakes showed the significant reduction in Tc in susceptibility measurements The total instrumental energy resolution was ~5 meV Angular resolution was better than ~0.15° and 0.4° along and perpendicular to the slit of the analyzer The ARPES estimate of Tc of the overdoped surfaces was within ±4 K except for the two samples falling outside of the SC dome for which the estimate was limited by the base temperature that could be reached with our cryostat (12 and 15 K Comparison of the underlying gapped FS with the gapless FS a FS contour in the superconducting state and b fully enclosed FS contour obtained in the normal state at T = 140 K (>T*) for the as grown sample The TB parameters are identical in both panels c Constant energy contour at E = 0 and d at E = −25 meV in the superconducting state (T = 20 K) of the underdoped sample e The normal state contour at E = 0 of the same sample (T = 125 K) g show the photoemission intensities along the momentum lines indicated in d kx = −0.7 πa−1 in the superconducting and normal states h Momentum distribution curves at E = −25 meV and at E = 0 with the maxima corresponding to the gapped and gapless Fermi momenta from f and g The bare in-plane band structure of Bi2212 used to fit the experimental FS contours is approximated by the tight-binding formula: where the index A (B) is for anti-bonding (bonding) state and μ is chemical potential. The hopping parameters that best describe the FSs of selected measured samples are given in Table 1 of this method is very close to that estimated from the experimental momentum width of the FS The data that support the findings of this study are available from the corresponding author upon reasonable request. The source data underlying Figs. 2j and 3a, b are provided as a Source Data file Anomalously large gap anisotropy in the a - b plane of Bi2Sr2CaCu2O8+δ Unconventional electronic structure evolution with hole doping in Bi2Sr2CaCu2O8+δ: angle-resolved photoemission results Pseudogap precursor of the superconducting gap in under- and overdoped Bi2Sr2CaCu2O8+δ Evidence for quantum critical behavior in the optimally doped cuprate Bi2Sr2CaCu2O8+δ Doping and temperature dependence of the mass enhancement observed in the cuprate Bi2Sr2CaCu2O8+δ Reconstructed Fermi surface of underdoped Bi2Sr2CaCu2O8+δ cuprate superconductors Simultaneous transitions in cuprate momentum-space topology and electronic symmetry breaking Superconducting properties of La2−xBaxCuO4 From a single-band metal to a high-temperature superconductor via two thermal phase transitions Phenomenological models for the gap anisotropy of Bi2Sr2CaCu2O8+δ as measured by angle-resolved photoemission spectroscopy Electronic excitations in Bi2Sr2CaCu2O8+δ : Fermi surface Evolution of the Hall coefficient and the peculiar electronic structure of the cuprate superconductors Interplay of externally doped and thermally activated holes in La2−xSrxCuO4 and their impact on the pseudogap crossover Change of carrier density at the pseudogap critical point of a cuprate superconductor Long-range incommensurate charge uctuations in (Y,Nd)Ba2Cu3O6+x Magnetic-field-induced charge-stripe order in the high-temperature superconductor YBa2Cu3Oy Charge order driven by Fermi-arc instability in Bi2Sr2−xLaxCuO6+δ Hole-concentration dependence of band structure in (Bi,Pb)2(Sr,La)2CuO6+δ determined by the angle-resolved photoemission spectroscopy Evolution of the pseudogap from Fermi arcs to the nodal liquid The origin and non-quasiparticle nature of Fermi arcs in Bi2Sr2CaCu2O8+δ Pseudogap opening and formation of Fermi arcs as an orbital-selective Mott transition in momentum space Phenomenological theory of the pseudogap state Quantum oscillations in a biaxial pair density wave state Quasiparticle and Josephson tunneling of overdoped Bi2Sr2CaCu2O8+δ single crystals Quasiparticle liquid in the highly overdoped Bi2Sr2CaCu2O8+δ High-transition-temperature superconductivity in the absence of the magnetic-resonance mode Visualizing pair formation on the atomic scale in the high-Tc superconductor Bi2Sr2CaCu2O8+δ Collapse of the normal-state pseudogap at a Lifshitz transition in the Bi2Sr2CaCu2O8+δ cuprate superconductor In situ carrier tuning in high temperature superconductor Bi2Sr2CaCu2O8+δ by potassium deposition Kim, C. K. et al. In-situ angle-resolved photoemission spectroscopy of copper-oxide thin films synthesized by molecular beam epitaxy. J. Electron Spectros. Relat. Phenomena, https://doi.org/10.1016/j.elspec.2018.07.003 (2018) Pelc, P. et al. Unusual behavior of cuprates explained by heterogeneous charge localization. Preprint at https://arxiv.org/abs/1710.10221 (2017) Download references acknowledges the generous financial support of the BNL Gertrude and Maurice Goldhaber Distinguished Fellowship Laboratory of Atomic and Solid State Physics grew the bulk crystals and performed magnetization measurements analyzed and interpreted data and wrote the manuscript Reprints and permissions Download citation DOI: https://doi.org/10.1038/s41467-018-07686-w Journal of Superconductivity and Novel Magnetism (2022) Metrics details The superconductor-insulator transition in two dimensions is a prototype continuous quantum phase transition at absolute zero driven by a parameter other than temperature Here we reveal this transition in one unit-cell Bi2.1Sr1.9CaCu2O8+x by space charge doping a field effect electrostatic doping technique We determine the related critical parameters and develop a reliable way to estimate doping in the nonsuperconducting region a crucial and central problem in these materials Finite-size scaling analysis yields a critical doping of 0.057 holes/Cu a critical resistance of ~6.85 kΩ and a scaling exponent product νz ~ 1.57 together with earlier work in other materials provide a coherent picture of the superconductor-insulator transition and its bosonic nature in the underdoped regime of emerging superconductivity in high critical temperature superconductors improvements in extreme electrostatic doping techniques have provided access to the carrier density driven SIT in La2−xSrxCuO4 (LSCO) and YBa2Cu3O7−x (YBCO) Universality of the QPT should imply Rc ~ 6.45 kΩ and a similar value for νz in different materials Thus establishing this benchmark in BSCCO is necessary and the measurement should avoid pitfalls from sample dependent imperfections which tend to overshadow material parameters Can this be extended to the strongly undoped nonsuperconducting region We show here that it can and indeed gives a reliable determination of doping which could profitably be used in future work a Dependence of 1/qRH on p = S/RS(Tf) for device F of this work and devices C Inset: Dependence of 1/qRH on 1/RS(200 K) showing linear behavior b Superconducting dome as a function of Tc and of doping p as calculated above for devices C Inset: Critical temperature Tc as a function of 1/RS(200 K) showing a linear dependence in the neighborhood of zero Tc Superconducting dome as a function of critical temperature and doping Inset: Superconducting phase diagram for four devices C a Doping dependence of isothermal sheet resistance from 7 to 20 K The dots are extracted from RS(T) data and the lines are splined guides for the eye b Universal finite-size scaling function at the SIT with t = T−1/νz Inset: The linear relation between T and t and between 9 and 15 K when the data is plotted on a log-log scale From the slope we obtain the critical exponent product νz = 1.57 ± 0.10 and removes the sample dependent uncertainty that comes from chemical doping The precursor on the glass substrate is placed between two electrodes and heated to ~180 ∘C to activate the Na+ mobility On the application of a negative gate voltage (~500 V) at the back side of the glass substrate the Na+ ions in the glass move away from the glass-sample interface forming an O2− space charge at the sample-glass interface This space charge sticks the first few nm of the precursor electrostatically on the glass substrate Adhesive tape is used to exfoliate the precursor the thickness of which is evaluated by Atomic Force Microscopy and optical contrast The sample is then annealed in air at 350 ∘C for 1 min to reduce its doping level by oxygen loss The device was finally put into a high-vacuum Oxford He-flow cryostat for transport measurements between 6 and 350 K and Hall measurements The measurements were performed with a DC current of 1 to 10 μA An external magnetic field of up to 2 T perpendicular to the sample plane was supplied by a resistive electromagnet The relevant datasets are available on request from the corresponding authors Superconductor-insulator transitions in the two-dimensional limit Thickness–magnetic field phase diagram at the superconductor-insulator transition in 2d High-temperature interface superconductivity between metallic and insulating copper oxides Two-dimensional superconductivity at a mott insulator/band insulator interface LaTiO3/SrTiO3 Multiple quantum criticality in a two-dimensional superconductor Superconductor-insulator transition in La2-xSr xCuO4 at the pair quantum resistance Electrostatic control of the evolution from a superconducting phase to an insulating phase in ultrathin YBa2Cu3O7-x films Comprehensive phase diagram of two-dimensional space charge doped Bi2Sr2CaCu2O8+x Crossover to strange metal phase: quantum criticality in one unit cell Bi2Sr2CaCu2O8+x High-temperature superconductivity in monolayer Bi2Sr2CaCu2O8+δ Magnetic-field-induced quantum superconductor-insulator transition in Nb0.15 Si0.85 Approach to a superconductor-to-Bose-insulator transition in disordered films Suppression of 2D superconductivity by the magnetic field: quantum corrections vs Onset of a boson mode at the superconducting critical point of underdoped YBa2Cu3Oy Liquid-gated interface superconductivity on an atomically flat film Presence of quantum diffusion in two dimensions: universal resistance at the superconductor-insulator transition Electrostatic tuning of the electrical properties of YBa2Cu3O7-x using an ionic liquid General trends in oxygen stoichiometry effects on Tc in Bi and Tl superconductors Indications of an electronic phase transition in two-dimensional superconducting YBa2Cu3O7-x thin films induced by electrostatic doping High quality 2d crystals made by anodic bonding: A general technique for layered materials Space charge induced electrostatic doping of two-dimensional materials: graphene as a case study Onset of two-dimensional superconductivity in space charge doped few-layer molybdenum disulfide c-axis resistivity of Bi2Sr2CaCu2Oy thin films at various oxygen doping: phase diagram and scaling law Evolution of the resistivity of single-layer Bi2Sr1.6La0.4CuOy thin films with doping and phase diagram Electron pairing in the pseudogap state revealed by shot noise in copper oxide junctions Superconductor–insulator quantum phase transition Quantum percolation and plateau transitions in the quantum hall effect Finite-size scaling study of the three-dimensional classical xy model Colloquium: anomalous metals: failed superconductors Self-duality and a Hall-insulator phase near the superconductor-to-insulator transition in indium-oxide films Oxygen displacement in cuprates under ionic liquid field-effect gating Metal-insulator transition induced by oxygen vacancies from electrochemical reaction in ionic liquid-gated manganite films In operando evidence of deoxygenation in ionic liquid gating of YBa2Cu3O7-X Suppression of ionic liquid gate-induced metallization of SrTiO 3(001) by oxygen Suppression of metal-insulator transition in vo2 by electric field–induced oxygen vacancy formation Download references We thank the Labex Matisse and the China Scholarship Council for support and Institut des NanoSciences de Paris for access to the electromagnet facility We acknowledge the Consortium des salles blanches d’Ile de France Palomo for access to clean room facilities de Physique des Matériaux et de Cosmochimie Walther Meissner Institut fur Tieftemperaturforschung synthesized the BSCCO single crystal precursors fabricated the devices and performed the measurements Peer review information Nature Communications thanks the anonymous reviewers for their contribution to the peer review of this work Download citation DOI: https://doi.org/10.1038/s41467-021-23183-z Metrics details This method does not rely on sophisticated equipment and the treatment cycle is short and inexpensive encouraging us to treat high-temperature superconductors with explosion energy XRD pattern and Rietveld refinement of pristine and shockwave-treated samples (a) Original XRD pattern of the pristine (black line) and the treated (red line) samples; the asterisks represent the newly produced phase Corresponding Rietveld refinement results for the pristine sample (b) and the treated sample (c) blue curves represent the difference between experimental and fitting results and short vertical lines are the predicted positions of the diffraction peaks Flux-exclusion and electrical measurements of the pristine and shockwave-treated samples (a) Magnetization-temperature curves of Bi2212 before and after the shockwave treatment Blue and red lines represent the relationships between resistivity and temperature of the pristine and treated samples IDS–VDS characteristics of the pristine and shockwave-treated samples measured at different VGS (b) IDS–VDS curves of the original powder device The gate voltage changes from 0 V to 15 V in steps of 5 V (c) IDS–VDS curves of the device fabricated using shockwave-treated material The gate voltage changes from -5 V to 5 V in steps of 2 V we have used a new shockwave method to modify some of the properties of polycrystalline superconducting oxide Bi2212 A fraction of the Bi2212 phase was transformed into the semiconducting Bi2201 phase under high temperature and pressure; trace amounts of other phases such as the Bi2223 superconducting phase were also present The mechanism proposed for the formation of Bi2201 is the compression in the c-axis direction resulting in a short c dimension of 20.10 Å in Bi2201 versus 30.93 Å in Bi2212 The diamagnetism critical temperature of the sample was improved from 84 K to 94 K It is possible that a change in the oxygen content of the Bi2212 contributed to the enhancement of the transition temperature The shockwave-treated sample exhibits apparent n-type semiconductor behavior with an on-off ratio a high as 5; by contrast the pristine sample shows obvious metallic-like properties and CuO were used to prepare the samples in this work These materials were weighed in the appropriate proportions according to nominal composition Bi2.1Sr1.9CaCu2O8+x and then mixed and calcined at 1023 K The homogenous mixture was pressed into sticks using static pressure and then calcined at 1123 K the sticks were milled into powders for the subsequent shockwave treatment Thermal initiation of detonation (the assembled installation was placed into a heating furnace and heated to explosion) was adopted to allow the explosion occur synchronously in both directions The explosion action was divided into three stages: first multiple reflection of the blast wave and third The detonation velocity was approximately 8310 m/s The maximum effective detonation pressure calculated by one-dimensional steady C-J detonation theory ($P=\frac{1}{4}{\rho }_{0}{D}^{2}$) was 31.4 GPa which is consistent with the end pressure of powder grain Bi2212 measured by Manganin gauge the explosive device was naturally cooled to room temperature in the furnace by turning the power off The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request Download references This work was supported by the National Natural Science Foundation of China (11572292) School of Chemical Engineering and Environment conducted the explosive experiments and was assisted by Y.L conducted the TEM experiments and prepared the manuscript The authors declare that they have no competing interests Download citation DOI: https://doi.org/10.1038/s41598-017-06887-5 Metrics details The silver migration effect into the metastable phase forms a micro-electric path to enhance the relative dielectric permittivity of CaCu3Ti4O12 ceramics for electronic devices Controlling the sintering time uniquely develops the metastable phase of as-sintered CaCu3Ti4O12 ceramics A post-heating process that applies the migration of silver into the metastable phase increases the relative dielectric permittivity the relative dielectric permittivity at room temperature of the silver-migrated CaCu3Ti4O12 ceramics sintered for 2 h is 565.9 × 103 almost 52 times higher than that of the as-sintered CaCu3Ti4O12 ceramics The selected area electron diffraction (SAED) patterns of the large and small grains were similar but differed from those of the metastable region including the grain boundary of the as-sintered CaCu3Ti4O12 ceramics sintered for 2 h by TEM technique This phenomenon suggests that enabling Ag-migration into the metastable phase develops a micro-electric path that improves the relative dielectric permittivity of CaCu3Ti4O12 ceramics Ag was selected as the electrode and material for migration The Ag-migration effects of CCTO ceramics that have a metastable phase can increase their relative dielectric permittivity We assumed that migrating the metallic component into the metastable phase in the ceramic component no experimental studies have been carried out on the difference in behavior between the migration effect and the dielectric property of CCTO ceramics This study controlled the sintering time at the optimized sintering temperature to observe the various phase conditions Measurement of the relative dielectric permittivity energy dispersive spectroscopy (EDS) and current density–electric field (J–E) properties in the fully sintered phase and partially sintered phase enabled the Ag-migration effect in CCTO to be analyzed and characterized Surface morphology and chemical composition with various sintering times Plane-view FE-SEM and EDS micrographs of the as-sintered CaCu3Ti4O12 ceramics sintered at 1125 °C in air for (a) 0.5 h and (c) 12 h corresponding to the X-ray maps of calcium (Ca) (a) Phase relations in the ternary system CaO-CuO-TiO2 for theoretical Ca1Cu3Ti4O12 ceramics and 12 h sintered CaCu3Ti4O12 ceramics depending on position (b) X-ray diffraction profiles of the as-sintered CaCu3Ti4O12 ceramics sintered at 1125 °C in air for 0.5 h We believe that this Cu rich region could form the metastable phase during the sintering process In contrast to the 2 h sintered CCTO ceramics no metastable phase region was observed in the CCTO ceramics sintered for 0.5 h and 12 h The different grain size distribution and chemical composition of the CCTO specimens as a result of the different sintering times may have caused the differences in their dielectric and electrical properties after the Ag-migration process the phases of all grains except for the metastable phase are close to theoretical Ca1Cu3Ti4O12 phase It means that there is less possibility of the secondary phase existence in 0.5 h and 12 h sintered CCTO than 2 h sintered CCTO that has metastable phase TiO2 and CuO phases appear in the 2 h sintered CCTO ceramics which can be attributed to the separated Cu phase EDS analysis of FE-SEM images for the CaCu3Ti4O12 ceramics sintered at 1125 °C for (a) and (b) 0.5 h and (e) and (f) 12 h after the Ag-migration process at 700 °C in air for 1 h Frequency dependence of the relative dielectric permittivity and dielectric loss for the (a) as-sintered and (b) Ag-migrated CaCu3Ti4O12 ceramics sintered at 1125 °C in air for 0.5 h Cole-Cole plots of the (a) as-sintered The insets show the magnified views of the high-frequency region close to the origin Current density versus electric field of the (c) as-sintered with the increase in relative dielectric permittivity the 2 h sintered CCTO showed the highest current density among the three specimens and the leakage current density reached almost 884 times higher than that of the as-sintered CCTO ceramic measured at 60 V/cm after the Ag-migration process the 0.5 h sintered CCTO ceramics showed a higher leakage current density than that of the 12 h sintered CCTO ceramics These results indicate that the Ag-migration effect into the metastable phase We believe this increased leakage current density probably derived from the developed micro-electric path into the metastable phase during the post-heating process Figure 7 shows a schematic of the Ag-migration into the metastable phase region including a grain boundary for the 2 h sintered CCTO ceramics. The post-heating process can migrate Ag material into the metastable region, and form a micro-electric path through the metastable phase and grain boundary region. Schematic of the Ag-migration phenomenon into metastable phase including grain boundary for the 2 h sintered CaCu3Ti4O12 ceramics We reported on the Ag-doping effect to CCTO ceramics on microstructure and dielectric properties32 The surface morphologies of 1–4 mol% Ag-doped CCTO ceramics sintered at temperatures from 975 to 1125 °C for 12 h were investigated The sintering temperature was decreased by Ag dopant as a sintering aid in the CCTO ceramics the relative dielectric permittivity of Ag-doped CCTO ceramic was increased Although the low sintering temperature and dielectric properties were improve by Ag-doping effect it is different from the Ag-migration effect to CCTO ceramics the metastable phase of CCTO ceramics can be achieved by controlling the sintering time a post-heating process at 700 °C for 1 h was employed to migrate the Ag materials into the CCTO ceramics we artificially controlled Ag-migration into the metastable phase region which could generate the micro-electric path; as a result we could increase the relative dielectric permittivity by a large margin It is strongly suggested that developing the micro-electric path through the Ag-migration process into the metastable phase and grain boundaries can colossally increase the relative dielectric permittivity of the CCTO ceramics Therefore for electronic device applications the Ag-migration process into the metastable phase can be performed introducing a micro-electric path to enhance the relative dielectric permittivity the metastable phase of CCTO ceramics was designed and prepared with the intention of employing the Ag-migration process to develop a micro-electric path into the CCTO ceramics We modulated the sintering time to prepare the metastable phase of CCTO ceramics The EDS analysis revealed the metastable phase in the 2 h sintered CCTO ceramics; therefore the post-heating process migrated Ag into the metastable phase the Ag element was detected in the grain boundary of CCTO ceramics sintered for 0.5 h and 12 h Development of the micro-electric path through the Ag-migration process colossally increased the relative dielectric permittivity of the 2 h sintered CCTO ceramics Impedance spectroscopy and J–E plot results support that the Ag-migration phenomenon occurs into the metastable phase and grain boundary rather than in the more stable CCTO phase to grain region Ag-migration into the metastable phase by the post-heating process in CCTO ceramics develops the micro-electric path to promote colossal relative dielectric permittivity CaCu3Ti4O12 powders were prepared by employing Ca(OH)2 (Aldrich These stoichiometric powders were ball-milled using ZrO2 balls with ethyl alcohol for 24 h The dried powders were calcined at 900 °C in air for 12 h at a rate of 5 °C/min and then slowly cooled to room temperature The CCTO powder was pressed (1 ton) into cylindrical pellets of 12 mm diameter and 1.5 mm thickness The pellets were sintered in an electrical furnace at 1125 °C for 0.5 h In order to measure the dielectric properties and metallic migration the polished CCTO specimens were coated with a conducting silver paste The Ag-coated CCTO specimens were post-heated at 700 °C in air for 1 h to achieve Ag migration The EDS experimental analysis showed migrated Ag in the metastable phase and grain boundaries and complex impedance of the CCTO specimens were measured by employing an Agilent 4294A precision impedance analyzer (40 Hz–110 MHz) The complex impedance (${Z}^{\ast }$) was calculated using the expression and Z′ and Z″ are the real and imaginary parts of the complex impedance Transmission electron microscopy (TEM; Tecnai F30 ST field-emission gun instrument) was used to observe the atomic arrangement and SAED patterns UK) was performed to investigate the chemical compositions of the CCTO ceramics The electric field dependent leakage current density (J–E) characteristic at room temperature was measured by Keithley 6517 A electrometer/high resistance meter Optical response of high-dielectric-constant perovskite-related oxide High Dielectric constant in ACu3Ti4O12 and ACu3Ti3FeO12 phases Giant dielectric constant response in a copper-titanate Strong nonlinear current–voltage behaviour in perovskite-derivative calcium copper titanate Giant barrier layer capacitance effects in CaCu3Ti4O12 ceramics CaCu3Ti4O12: One-step internal barrier layer capacitor Dielectric behavior of CCTO/epoxy and Al-CCTO/epoxy composites New percolative BaTiO3-Ni composites with a high and frequency-independent dielectric constant (εr ≈ 80000) Enhanced dielectric properties of low-temperature sintered SrBi2Nb2O9/Ag composites High dielectric permittivity and Low percolation threshold in nanocomposites based on poly(vinylidenefluoride) and exfoliated graphite nanoplates Physics of inhomogeneous inorganic materials New metastable phases in binary tin alloy systems Formation of metastable phases in flame- and plasma-prepared alumina and formation of metastable phases: Insights from nanocrystalline TiO2 Role of metastable phases in the spontaneous precipitation of calcium carbonate Grain size effects on the dielectric properties of CaCu3Ti4O12 ceramics for supercapacitor applications Infuence of silver migration on dielectric properties and reliability of relaxor based MLCCs Migration of nickel and titanium oxide species as studied by in situ scanning transmission electron microscopy Sintering dense nanocrystalline ceramics without final-stage grain growth Gibbs energy of formation of CaCu3Ti4O12 and phase relations in the system CaO–CuO/Cu2O–TiO2 Subsolidus Phase Relationship in the CaO–CuO–TiO2 Ternary System at 950 °C in Air The influence of the segregation of Cu-rich phase on the microstructural and impedance characteristics of CaCu3Ti4O12 ceramics Role of mixing mediums in the synthesis of single phase CaCu3Ti4O12 (CCTO) Evidence for power-law frequency dependence of intrinsic dielectric response in the CaCu3Ti4O12 Defect structure of the high-dielectric-constant perovskite CaCu3Ti4O12 Direct evidence for atomic defects in graphene layers Nanoscale disorder and local electronic properties of CaCu3Ti4O12: An integrated study of electron Effect of sintering conditions on microstructure and dielectric properties of CaCu3Ti4O12 (CCTO) ceramics Dielectric properties of Ag-doped 0.94(K0.5Na0.5)NbO3–0.06LiNbO3 ceramics prepared by templated grain growth and impedance spectroscopy of CaCu3Ti4O12 ceramics prepared by sol–gel process Enhanced dielectric properties of Ag-doped CCTO ceramics for energy storage devices Download references This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Science ICT & Future Planning (2016R1A2B4011892) School of Electrical and Electronics Engineering Korea Electrotechnology Research Institute synthesized and characterized the CCTO ceramics Publisher's note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations Download citation DOI: https://doi.org/10.1038/s41598-018-19241-0 Metrics details The primordial ingredient of cuprate superconductivity is the CuO2 unit cell Theories usually concentrate on the intra-atom Coulombic interactions dominating the 3d9 and 3d10 configurations of each copper ion if Coulombic interactions also occur between electrons of the 2p6 orbitals of each planar oxygen atom spontaneous orbital ordering may split their energy levels This long-predicted intra-unit-cell symmetry breaking should generate an orbitally ordered phase for which the charge transfer energy ε separating the 2p6 and 3d10 orbitals is distinct for the two oxygen atoms Here we introduce sublattice-resolved ε(r) imaging to CuO2 studies and discover intra-unit-cell rotational symmetry breaking of ε(r) this state is arranged in disordered Ising domains of orthogonally oriented orbital order bounded by dopant ions and within whose domain walls low-energy electronic quadrupolar two-level systems occur these data reveal a Q = 0 orbitally ordered state that splits the oxygen energy levels by ~50 meV analogous intra-unit-cell orbital ordering for Cu-based high-temperature superconductive materials has never been observed LHB represents the lower Hubbard band and UHB represents the upper Hubbard band Source data no microscopic mechanism has yet been experimentally established for this CuO2 nematic phase Here the 2p6 orbital of the oxygen atom along the CuO2 x axis (Ox site) is separated from the upper Cu band by the charge transfer energy εx whereas the notionally equivalent oxygen orbital along the y axis (Oy site) exhibits a different charge transfer energy εy Our objective is then a direct search for such rotational symmetry breaking at the charge transfer energy scale by the visualization of ε within each CuO2 unit cell to estimate the variations in the charge transfer energy away from its mean supermodulation has no discernable influence on the intra-unit-cell symmetry breaking of δε(r) High-voltage differential conductance spectra g(r whereas the spatially averaged spectrum $\overline{g\left(V\right)}$ is shown as a dashed curve The example spectrum is measured at a location (yellow dot) in a Such high junction resistances of 85 GΩ or large tip–sample distances preclude the effects of the tip–sample electric field on g(V) The separation between the lower and upper bands is clearly visible for the example spectrum (blue arrows) as well as for the average spectrum (red double-headed arrow) Visualization of charge transfer energy variations δε(r) from a Histogram of charge transfer energy variations δε in c PSD Fourier transform T(q) of the topograph measured simultaneously as c The QSM peaks (orange arrow) signify the supermodulation the PSD T(q) does not break C4 symmetry at its Bragg peaks PSD Fourier transform δε(q) of charge transfer energy map from c The δε(q) breaks C4 symmetry at its Bragg peaks as the plots of δε(q) are distinct at Qx = (1 This is direct evidence of intra-unit-cell rotational symmetry breaking at the charge transfer energy in cuprates Source data Source data Source data orbital order between oxygen orbitals at the two separate oxygen sites of CuO2 is highly consistent with the observed intra-unit-cell rotational symmetry breaking of ε(r) that splits the energy between the two oxygen atoms by ~50 meV in Bi2Sr2CaCu2O8+x The edges of the filled lower band and the empty upper band can be identified from the appearance of an extremely rapid increase in the density of states Here the value of charge transfer energy ε(r) is estimated at every location by subtracting these band edges at a constant differential conductance (G ≈ 20 pS) as follows: the δε(r) histogram features a narrower σ and therefore yields a higher signal-to-noise ratio we implement our algorithm to measure the charge transfer energy variation δε(r) throughout The averaged differential conductance g(V) is shown as a dashed curve in Extended Data Fig. 1f,g The variations in charge transfer energy are determined from the deviation of a point spectrum from the averaged spectrum The states on the V > 0 side have a positive integral ${I}_{+}\left({\bf{r}}\right)={\int }_{0}^{{V}_{\max }}g(V,{\bf{r}}){{\rm{d}}V}$ The states on the V < 0 side have a negative integral ${I}_{-}\left({\bf{r}}\right)={\int }_{{V}_{\min }}^{0}g(V,{\bf{r}})$ where the minimum energy is Vmin = –1.6 V The variation in each integral I+(r) and I–(r) from the average values $\bar{{I}_{+}}$ and $\bar{{I}_{\pm }}$ occurs due to the variation in energy separation δε(r) between the lower and upper bands from its average value To efficiently evaluate the energy splitting between the point spectrum and averaged spectrum the integral difference is normalized by the difference between the maximum differential conductance gmax and the minimum difference conductance gmin Here gmax = 0.220 nS is given by the maximum of the FOV-averaged spectrum and gmin = 0.009 nS is the minimum differential conductance of the averaged spectrum There are the two typical cases shown in Extended Data Fig. 1f,g All the transformation parameters applied to T2′(r) are subsequently applied to the high-voltage differential conductance map g′(r V) that is simultaneously measured with the topography The offset of the two registered images are within three pixels meaning that the precision of registration is better than 80 pm everywhere in the whole FOV δε′(r) is calculated from the unprocessed dataset and δε(r) is calculated from the LF-corrected and registered dataset The Fourier transform δε′(q) of the unprocessed data shows anisotropy at the Bragg peaks The processed data δε(q) shows the same anisotropic Bragg peaks and the background noise is much lower in the drift-corrected data than in the unprocessed data the LF algorithm does not alter the conclusion that C4 symmetry is broken in δε These linecuts quantitatively and clearly show that Qx ≈ Qy in T(q) of all the FOVs This confirms that the tip and lattice preserve C4 symmetry which is consistent with the anisotropy in charge transfer energy variations δε the anisotropy in Bragg peaks of the charge transfer energy variations δε is repeatable in multiple experiments at the same hole density The δε values from independent FOVs show similar statistics The nematicity is not generated by the crystallography or the scanning tip the Fourier analysis of δε appears robust and reliable value of the IUC energy splitting between the Ox and Oy sites ranges from 20 to 30 meV The tip preserves IUC rotational symmetry and the crystallography of the CuO2 unit cell does not break rotational symmetry These same phenomena are omnipresent throughout the FOVs in the experiment meaning that orbital ordering is universal which means that the Oy sites have higher charge transfer energy than the Ox sites in this domain The two domains are separated by a domain wall Such domains are observed throughout the unprocessed data showing the intra-unit-cell symmetry breaking and Ising domains of orbital ordering we see that the oxygen dopants are near the Nε domain walls (yellow contours) The distribution of ddopant is different from drandom with regard to two aspects Although the ddopant distribution has a sharp peak at 1.6 Å the drandom distribution has a blunt plateau The deviation in the distance distribution clearly indicates that the oxygen dopants are located near the domain walls of the orbitally ordered domains providing statistical evidence that they are pinning the nematic domains A total of 237 oxygen dopants are studied in the total histogram The data shown in the main figures are available via Zenodo at https://doi.org/10.5281/zenodo.10510971. Source data are provided with this paper The code is available via Zenodo at https://doi.org/10.5281/zenodo.10515736 Colloquium: theory of intertwined orders in high temperature superconductors Quasi-one-dimensional dynamics and nematic phases in the two-dimensional Emery model Mean-field analysis of intra-unit-cell order in the Emery model of the CuO2 plane Nematic and spin-charge orders driven by hole-doping a charge-transfer insulator Pairing interaction near a nematic quantum critical point of a three-band CuO2 model Multistage electronic nematic transitions in cuprate superconductors: a functional-renormalization-group analysis Magnetic orders in the hole-doped three-band Hubbard model: spin spirals Theoretical insights into electronic nematic order Spin-orbital frustrations and anomalous metallic state in iron-pnictide superconductors Orbital ordering induces structural phase transition and the resistivity anomaly in iron pnictides Ferro-orbital order and strong magnetic anisotropy in the parent compounds of iron-pnictide superconductors What drives nematic order in iron-based superconductors Gap symmetry and structure of Fe-based superconductors Discovery of orbital-selective Cooper pairing in FeSe Role of the orbital degree of freedom in iron-based superconductors Iron pnictides and chalcogenides: a new paradigm for superconductivity Theory of high-Tc superconductivity in oxides Pairing instabilities of the extended Hubbard model for Cu-O based superconductors The doping dependence of T*—what is the real high-Tc phase diagram Nematic Fermi fluids in condensed matter physics Visualizing the evolution from the Mott insulator to a charge-ordered insulator in lightly doped cuprates Relationship between the parent charge transfer gap and maximum transition temperature in cuprates On the electron pairing mechanism of copper-oxide high temperature superconductivity Direct phase-sensitive identification of a d-form factor density wave in underdoped cuprates Atomic-scale electronic structure of the cuprate d-symmetry form factor density wave state Topological defects coupling smectic modulations to intra-unit-cell nematicity in cuprates Evidence for a vestigial nematic state in the cuprate pseudogap phase Nematicity in stripe-ordered cuprates probed via resonant X-ray scattering Quenched disorder and vestigial nematicity in the pseudogap regime of the cuprates Emergent charge order from correlated electron-phonon physics in cuprates Visualization of the emergence of the pseudogap state and the evolution to superconductivity in a lightly hole-doped Mott insulator Revealing the Coulomb interaction strength in a cuprate superconductor Optical conductivity spectra and electronic structure of Bi2Sr2(Y1–xCax)Cu2Oy system Magnetic order in the pseudogap phase of high-Tc superconductors Observation of magnetic order in a superconducting YBa2Cu3O6.6 single crystal using polarized neutron scattering Unusual magnetic order in the pseudogap region of the superconductor HgBa2CuO4+δ Magnetic order in the pseudogap phase of HgBa2CuO4+δ studied by spin-polarized neutron diffraction Intra-unit-cell magnetic correlations near optimal doping in YBa2Cu3O6.85 a-b anisotropy of the intra-unit-cell magnetic order in YBa2Cu3O6.6 Spontaneous breaking of time-reversal symmetry in the pseudogap state of a high-Tc superconductor Nematicity in a cuprate superconductor revealed by angle-resolved photoemission spectroscopy under uniaxial strain Thermodynamic evidence for a nematic phase transition at the onset of the pseudogap in YBa2Cu3Oy Diagonal nematicity in the pseudogap phase of HgBa2CuO4+δ A global inversion-symmetry-broken phase inside the pseudogap region of YBa2Cu3Oy Nematic fluctuations in the cuprate superconductor Bi2Sr2CaCu2O8+δ Divergent nematic susceptibility near the pseudogap critical point in a cuprate superconductor Bounding the pseudogap with a line of phase transitions in YBa2Cu3O6+δ Orbital symmetry of charge-density-wave order in La1.875 Ba0.125CuO4 and YBa2Cu3O6.67 Vanishing nematic order beyond the pseudogap phase in overdoped cuprate superconductors Resonant X-ray scattering measurements of a spatial modulation of the Cu 3d and O 2p energies in stripe-ordered cuprate superconductors Critical nematic correlations throughout the doping range in Bi2−zPbzSr2−yLayCuO6+x Maximising the resolving power of the scanning tunneling microscope Download references acknowledge support from the Moore Foundation’s EPiQS Initiative through Grant GBMF9457 acknowledge support from the European Research Council (ERC) under award DLV-788932 acknowledges support from the Royal Society under award R64897 acknowledge support from the Science Foundation Ireland under award SFI 17/RP/5445 acknowledges support from the John Fell Fund at the University of Oxford under project 0010827 acknowledges support from the Office of Basic Energy Sciences Materials Sciences and Engineering Division acknowledges support from JSPS KAKENHI (no acknowledges support by QuantEmX grant GBMF9616 from ICAM/Moore Foundation and by a Visiting Fellowship at Wadham College This research programme was also advanced through support from the National Science Foundation under grant no NSF PHY-1748958 at the Kavli Institute for Theoretical Physics of University of California These authors contributed equally: Shuqiu Wang National Institute of Advanced Industrial Science and Technology (AIST) Max Planck Institute for Chemical Physics of Solids developed and carried out the comprehensive analysis supervised the research and wrote the paper with key contributions from S.W The manuscript reflects the contributions and ideas of all authors (a) Image of the charge transfer energy ${\varepsilon }\left({\boldsymbol{r}}\right)$ calculated from Eq. 4 The supermodulation (~150 meV) wavevector ${{\boldsymbol{Q}}}_{{\rm{SM}}}$ is masked in (a) such that the intra-unit-cell features (~50 meV) are revealed (b) Fourier transform of ${\varepsilon }\left({\boldsymbol{r}}\right)$ Linecut from (0,0) to the Bragg peaks in ${\varepsilon }\left({\boldsymbol{r}}\right)$ where the ratio of the Bragg peaks intensity $\frac{{{\boldsymbol{Q}}}_{y}}{{{\boldsymbol{Q}}}_{x}}=1.9$ indicates IUC symmetry breaking in charge transfer energy ${\varepsilon }\left({\boldsymbol{r}}\right)$ (d) Statistical distribution of ${\varepsilon }\left({\boldsymbol{r}}\right)$ (e) Statistical distribution of $\delta {\varepsilon }\left({\boldsymbol{r}}\right)$ The narrower distribution in $\delta {\varepsilon }\left({\boldsymbol{r}}\right)$ demonstrates an improvement in signal-to-noise ratio over the ${\varepsilon }\left({\boldsymbol{r}}\right)$ algorithm The histogram of $\delta {\varepsilon }\left({\boldsymbol{r}}\right)$ has a narrower σ than the histogram of ${\varepsilon }\left({\boldsymbol{r}}\right)$ demonstrating the signal-to-noise ratio is higher in the algorithm used here to measure the variations in charge transfer energy $\delta {\varepsilon }\left({\boldsymbol{r}}\right)$ Thus this $\delta {\varepsilon }\left({\boldsymbol{r}}\right)$ algorithm with higher SNR was used throughout this paper (f-g) Typical examples of the splitting of the charge transfer energy (f) shows a case when the energy variation is positive (g) shows a case when the energy variation is negative (a & b) Show two unprocessed low and high voltage topographs in the same field of view The low-voltage topograph T'1(r) (a) has atomic resolution and it allows Bi atoms to be identified (RN - 30 GΩ The high voltage topograph T'2(r) in (b) was acquired simultaneously with the electronic structure $g({\boldsymbol{r}},V)$ (RN - 85 GΩ The insets show the broad Bragg peaks of its topo (c) is an unprocessed map of the charge transfer energy $\delta {\varepsilon}^{\prime} \left({\boldsymbol{r}}\right)$ and (d) is the corresponding PSD Fourier transform $\delta {\varepsilon}^{\prime} \left({\boldsymbol{q}}\right)$ shows anisotropy between its Bragg peaks with $\frac{{{\boldsymbol{Q}}}_{y}}{{{\boldsymbol{Q}}}_{x}}=$ 2.0 (e & f) show the same topographs after Lawler-Fujita correction Insets show sharp Bragg peaks indicating that piezo drift has been corrected Inset: Zoom-in image (center) of the cross-correlation between ${T}_{1}\left({\boldsymbol{r}}\right)$ and ${T}_{2}\left({\boldsymbol{r}}\right)$ The maximum (annotated by the cross) has a width of 3 pixels The registration precision is better than 80 pm (equivalent to 1.5 pixels) (g) is $\delta {\varepsilon }\left({\boldsymbol{r}}\right)$ after Lawler-Fujita correction for piezo-drift and (h) the corresponding PSD Fourier transform The Bragg peaks are single pixel and IUC symmetry breaking remains present at the Bragg peaks with $\frac{{{\boldsymbol{Q}}}_{y}}{{{\boldsymbol{Q}}}_{x}}=1.9.$ The disorder at ${\boldsymbol{q}}=$ 0 has been noticeably reduced (a) Second FOV of Bi2Sr2CaCu2O8+x surface topography (c) Linecuts of $T\left({\boldsymbol{q}}\right)$ in Qx (red) and Qy (blue) directions show the ratio of the transverse averaged intensity at the Bragg peaks is $\frac{{{\boldsymbol{Q}}}_{y}}{{{\boldsymbol{Q}}}_{x}}=1.3$ (d) Second FOV of charge transfer energy variations (f) Linecuts of $\delta {\varepsilon }({\boldsymbol{q}})$ show $\frac{{{\boldsymbol{Q}}}_{y}}{{{\boldsymbol{Q}}}_{x}}=2.3$ and ${\delta {\varepsilon }}_{{RMS}}=95$ meV Thus the charge transfer energy variations break rotational symmetry (g) Nematicity analysis of the same FOV in (a) Image of oxygen-site-specific nematic order parameter ${N}_{\varepsilon }\left({\boldsymbol{r}}\right)$ The area ratio ${A}_{{red}}/{A}_{{blue}}$ is 1.8 Inset: histogram of ${N}_{\varepsilon }\left({\boldsymbol{r}}\right)$ whose RMS is ~28 meV (h-i) Unit cell averaged structure of charge transfer energy variations $\delta {\varepsilon }({\boldsymbol{r}})$ from two Ising domains Inset: unit cell averaged structure of $T\left({\boldsymbol{r}}\right)$ of each Ising domain The yellow circles represent the location of the Cu sites (a) Third FOV of Bi2Sr2CaCu2O8+x surface topography (c) Linecuts of $T({\boldsymbol{q}})$ show the ratio of the transverse averaged intensity at the Bragg peaks is $\frac{{{\boldsymbol{Q}}}_{y}}{{{\boldsymbol{Q}}}_{x}}=1.3$ (d) Third FOV of charge transfer energy variations (f) Linecuts of $\delta {\varepsilon }({\boldsymbol{q}})$ show the intensity ratio of $\frac{{{\boldsymbol{Q}}}_{y}}{{{\boldsymbol{Q}}}_{x}}=1.7$ and ${\delta {\varepsilon }}_{{RMS}}$ ${\rm{is}}$ $\sim 129$ meV The area ratio ${A}_{{red}}/{A}_{{blue}}$ is 2.3 Inset: histogram of ${N}_{\varepsilon }\left({\boldsymbol{r}}\right)$ whose RMS is ~34 meV Inset: unit cell averaged structure of $T\left({\boldsymbol{r}}\right)$ from each Ising domain (a) Fourth FOV of Bi2Sr2CaCu2O8+x surface topography (d) Fourth FOV of charge transfer energy variations (f) $\delta {\varepsilon }({\boldsymbol{q}})$ shows $\frac{{{\boldsymbol{Q}}}_{y}}{{{\boldsymbol{Q}}}_{x}}=1.8$ and ${\delta {\varepsilon }}_{{RMS}}\approx 105$ meV The area ratio ${A}_{{red}}/{A}_{{blue}}$ is 2.2 Inset: histogram of ${N}_{\varepsilon }\left({\boldsymbol{r}}\right)$ whose RMS is ~26 meV (h-i) Unit cell averaged structure of charge transfer energy variations $\delta {\varepsilon }({\boldsymbol{r}})$ Inset: unit cell averaged structure of $T\left({\boldsymbol{r}}\right)$ from the corresponding Ising domain i) First column: Topograph of the FOV where the spectra are measured j) Second column: Image of nematic intra-unit-cell order parameter ${N}_{\varepsilon }\left({\boldsymbol{r}}\right)$ sampled on oxygen sites k) Third column: 10 dI/dV point spectra sampled on the oxygen sites from Domain 1 in (b) Clearly these point spectra show the Ox spectra are shifted by -50 meV ~ -30 meV with respect to their intra-unit-cell Oy spectra The locations of the Ox and Oy sites are shown as circles in (a-b) l) Fourth column: 10 point spectra sampled on the oxygen sites from Domain 2 reveal that the Oy spectra are shifted by -50 meV ~ -30 meV with respect to the Ox spectra from the same unit cell The locations of the unit cell and oxygen sites are shown in circles in (a-b) The dI/dV splitting to opposite directions in the two different domains proves charge transfer energy splitting occurs in unprocessed differential conductance spectra (a–c) Three independent differential conductance maps $g\left({\boldsymbol{r}},-900{\rm{meV}}\right)$ where the locations of the oxygen dopants are identified as black circles Inset of (a) shows a typical dI/dV spectrum of an oxygen dopant (d–f) Oxygen-specific order parameter ${N}_{{\varepsilon }}\left({\boldsymbol{r}}\right)$ with overlaying oxygen dopants as black circles The ${N}_{{\varepsilon }}\left({\boldsymbol{r}}\right)$ are measured simultaneously as $g$(r (g–i) The ${d}_{{\rm{dopant}}}$ histogram (pink bar) is the distance from each dopant to the nearest location on the domain walls The ${d}_{{\rm{random}}}$ histogram (grey curve) is the expectations of the distance between simulated random points and its nearest point in the domain walls (a) Identification of the Cu site in the topograph $T\left({\boldsymbol{r}}\right)$ Each unit cell is defined by a Cu site (black circles) in the center and four Cu sites at the corners The averaged image of all the unit cells is a UCA image presented in the inset (b) The CuO2 unit cells are categorized into two zones of Ising domains from the parameter ${N}_{{\varepsilon }}\left({\boldsymbol{r}}\right)$ map The UCA images of each Ising domain is subsequently calculated i) show the topographs where the supermodulation is filtered j) present the topographs where the supermodulation is kept k) show the orbital ordering domains calculated from the topographs in the first column where the supermodulation is removed l) show the orbital ordering domains calculated from the topographs in the second column where the supermodulation remains The orbital ordering domains from the third (without supermodulation) and fourth columns (with supermodulation) are virtually identical The supermodulation has virtually no effect on the orbital-order parameter used in this paper Reprints and permissions Download citation DOI: https://doi.org/10.1038/s41563-024-01817-z The Kansas City Chiefs and San Francisco 49ers will face off in the Super Bowl this weekend but one KC-area credit union is already feeling like a winner Kan.-based CommunityAmerica Credit Union has been a Chiefs sponsor since 2016 but this NFL season marked the credit union’s first year as the team’s exclusive banking partner – as well as the Chiefs’ first visit to the Super Bowl in 50 years the big game offers the $3 billion-asset credit union a unique opportunity to build brand awareness at a time when much of the region is focused on the team “It’s been quite the ride – timing is everything,” quipped CACU’s VP of Marketing Matt Johnson speaking Friday morning while on his way to Arrowhead Stadium to catch a charter bus to Miami for Sunday’s game For more than a decade the credit union sponsored the Kansas City T-Bones and in 2015 management began examining strategic goals and long-term vision including how those applied to marketing and sponsorships Johnson likened the plan to “going from minor league to major league.” [Major League Soccer’s] Sporting Kansas City everything we could find in the city to see what we could partner with to elevate our brand and it boiled down to the Chiefs,” he said A CommunityAmerica Credit Union billboard featuring Kansas City Chiefs star Patrick Mahomes CACU became the team's official banking sponsor in 2019.Photo courtesy of CommunityAmerica Credit Union The primary goal for the Chiefs sponsorship has been to increase what Johnson called “unaided awareness” of the credit union and raise CommunityAmerica’s profile to the point where consumers rank it among the top three financial institutions in the region when surveyed by outside groups Johnson said CACU is currently ranked fourth “In 2015 we were sitting around 23% of unaided awareness and the goal was to get above 51% by 2025,” he said We’ve taken a huge jump but had plateaued for several years.” The Chiefs sponsorship has had other benefits “One unintended by product is that it has helped with recruiting,” he said “People want to work here and we’re getting top talent reaching out to us so if we have an open position we can be really selective about who we bring on.” Johnson and others at CommunityAmerica are rooting for the team to win president of South Carolina-based Your Marketing Co. “They’ve made it to the Super Bowl,” he said “The [New Orleans] Saints are my team and they haven’t been to the Super Bowl since they won it in 2009 I’d think with the Chiefs going to the Super Bowl even if they lose that’s pretty good for the team it has to boost morale … and that’s something [CACU] can take and run with long-term.” works with credit unions across the country but CACU is not one of its clients McDonald concurred that CommunityAmerica's timing couldn’t have been better – but he also said much of that just comes down to luck No matter how much research an institution puts into teams or organizations they sponsor “you’re pretty much at their mercy based on how they perform.” “The flip side of that is there are some teams that no matter how badly they do they still have a loyal fan base and continue to have heritage and presence in that market,” he said “Think of the Cleveland Browns – they still have season ticket holders; how do they do that The Chiefs are the third Kansas City-area club to make it to a championship game in the last decade after Sporting Kansas City’s MLS Cup win in 2013 and the Kansas City Royals’ World Series victory in 2015 Johnson said the local teams’ good run is also reflective of a city on the rise again “A lot of us really enjoy the fact that we’re considered flyover country yet here we are sitting on this gem of a city and this community,” he said “It’s funny to see our downtown skyline now We’ve got cranes with buildings going up and subdivisions being built because people want to move here and it’s been great to see the country start to embrace it and people want to be a part of it.” The big game’s final score won’t change any of that but some of CommunityAmerica’s future plans will depend on whether the Chiefs win or lose “If they will it’s going to be all Chiefs every day until next seasons starts and then we’ll do it all over again,” said Johnson but it's still high enough to be a fraud concern for banks The Trump administration's move to mandate digital could force banks to dump paper once and for all Artificial intelligence IBM and Box partner on enterprise AI for businesses The two companies are collaborating to bring enterprise AI to Box users Politics and policy Trump seeks 43% cut to HUD in 2026 budget plan The administration is pitching a $26.7 billion reduction to the regulator's funding for rental assistance public housing and elderly and disability housing FORECLOSURE WARS She stopped paying her mortgage more than 15 years ago Metrics details Growth of BSCCO whiskers. (a) Photograph of an amorphous BSCCO shard. (b) Photograph of grown whiskers on the shard following the annealing. (Inset) Single whisker. Scale - 1 sq. grid = 1 cm2. (c) SEM image of grown whiskers. (d) Optical image of device fabricated to measure electronic properties of exfoliated BSCCO thin flakes (D1). Structural characterization of BSCCO whiskers (a) Powder x-ray diffraction pattern of BSCCO whiskers The powder diffraction pattern shows (00l) plane as the preferred orientation where the thickness of the whisker corresponds to c-plane (b) HRTEM of BSCCO whiskers with incident beam parallel to c-axis (c) Cross-sectional TEM with incident beam perpendicular to c-axis Periodic lines at interval of 1.52 nm are visible (d) Electron-beam diffraction with incident beam parallel to c-axis HRTEM and electron-beam diffraction data suggest high crystalline quality of the whiskers Energy dispersive x-ray spectroscopy (EDX) was also used to analyze the elemental composition of grown whiskers The compositional spectrum values are provided in the Supplementary material Magnetic field dependent transport properties of exfoliated BSCCO flakes for the device D3 (a) Zero field four-probe I-V characteristics at 10 K (b) Similar excess current for the two voltage jumps in IVC taken at 10 K (c) Numerical derivative of IVCs at various B (d) Colorscale plot of numerical derivative Superconductivity is observed even at 12 T magnetic field All magnetic field measurements were performed at 10 K Download references We acknowledge funding from the Department of Atomic Energy and the Department of Science and Technology of the Government of India NK thanks SERB-DST for the financial support (project number: PDF/2016/000648) We thank Ruta Kulkarni for help in preparing the BSCCO shards and John Philip Mathew for assistance with electrical transport measurements Jangade and Nikhil Kumar contributed equally to this work Department of Condensed Matter Physics and Materials Science performed electrical measurements and analysed the data did the growth of the whiskers under the supervision of A.T assisted in fabrication of devices and electrical measurements did the TEM imaging and related sample preparation supervised the growth of whiskers and structural characterization supervised the device fabrication and electrical measurements wrote the manuscript; all authors provided input during manuscript preparation Download citation DOI: https://doi.org/10.1038/s41598-017-03408-2 Journal of Superconductivity and Novel Magnetism (2025) Journal of Superconductivity and Novel Magnetism (2019) Metrics details The relationship between the cuprate pseudogap (Δp) and superconducting gap (Δs) remains an unsolved mystery we present a temperature- and doping-dependent tunneling study of submicron Bi2Sr2CaCu2O8+δ intrinsic Josephson junctions which provides a clear evidence that Δs closes at a temperature Tc0 well above the superconducting transition temperature Tc but far below the pseudogap opening temperature T* We show that the superconducting pairing first occurs predominantly on a limited Fermi surface near the node below Tc0 accompanied by a Fermi arc due to the lifetime effects of quasiparticles and Cooper pairs The arc length has a linear temperature dependence and as temperature decreases below Tc it reduces to zero while pairing spreads to the antinodal region of the pseudogap leading to a d-wave superconducting gap on the entire Fermi surface at lower temperatures we address the issue using the temperature- and doping-dependent tunneling spectroscopy of submicron Bi2Sr2CaCu2O8+δ intrinsic Josephson junctions The data presented below were based on these works and extended to samples with different doping strength (a–d) doping strength increasing from underdoped (UD) to overdoped (OD) with Tc = 71 The spectra are presented with V corresponding to the voltage per junction and in each case are normalized to the respective ones at the pseudogap opening temperature T* = 310 showing that electron tunneling occurs between CuO2 double layers which form planar-type superconductor-insulator-superconductor (SIS) tunnel junctions The present work demonstrates that the superconducting gap Δs closes at a temperature Tc0 well above Tc but far below the pseudogap opening temperature T* which supports a two-gap picture with superconducting pairing persisting up to Tc0 The pairing is found to occur first on a limited Fermi surface near the node below Tc0 accompanied by a Fermi arc due to finite quasiparticle scattering rate and pair decay rate disappears gradually as temperature approaches Tc Measured and fitted quantities showing that the superconducting gap Δs closes at Tc0 (Tc < Tc0 < T*) (a–d) squares: half the conductance peak position in meV; up-triangles: superconducting gap Δs (solid) and lifetime parameter γs (open) obtained by fitting the normalized spectra σ(V ω) excluding the pseudogap-dominant region from 0 to θp on the Fermi surface Δs is seen to follow nicely the BCS d-wave gap (lines) closing at Tc0 = 150 In (c) Δs obtained from fit considering the entire Fermi surface is plotted as down-triangles for comparison (e) symbols and schematic gap profiles on the Fermi surface (yellow) in the temperature ranges of well below Tc (blue) and from Tc0 to T* (red) ω) is shown (green) with a Fermi arc as observed in ARPES experiment (f) Δs of the UD89K sample obtained from fits to the normalized σ(V Both deviate considerably from the BCS gap closing at respective temperatures (dashed and dotted lines) also in c) that shows a good agreement with the BCS prediction (solid line) above Tc (see text for more details) It is seen that the result deviates significantly from the dashed line which means that the single-gap picture does not lead to an appropriate description It can be seen that the fit is again unsatisfactory when compared to the BCS curve (dotted line) which shows a clear tendency of approaching the BCS solid line below Tc These two results can be naturally explained if the superconducting pairing gradually spreads to the antinode on the Fermi surface with θ < θp which is predominantly occupied by the pseudogap phase above Tc all the data above Tc show a compelling evidence that the superconducting gap Δs closes at Tc0 They demonstrate that the superconducting phase grows out from the pseudogap phase with Tc0 as the Cooper pair formation temperature which supports a two-gap picture with precursor pairing extending from above Tc up to Tc0 which leads to the further reduction of σ(0 The data are presented from 4.2 K up to the pseudogap opening temperature T* and are normalized to those at T* Arrows pointing upward and downward indicate Tc0 and Tc it continues to decrease to a value below Δs Solid lines are guides to the eye showing approximately the linear temperature dependence We have shown that for the four Bi2Sr2CaCu2O8+δ crystals with different doping levels the superconducting gap Δs closes at a temperature Tc0 well above the superconducting transition temperature Tc but far below the pseudogap opening temperature T* thus an extensive precursor pairing regime between Tc and Tc0 is demonstrated we present an alternative fitting procedure considering both the superconducting part (Δs which leads to the same conclusion as using the conventional approach of normalizing out the pseudogap contribution described above It is shown that Δp is nearly constant from slightly below Tc up to T* while γp experiences a continuous increase which is consistent with the filling-up character of the pseudogap as temperature approaches T* from below The differences and similarities in these ARPES and tunneling experiments remain to be explained in the future In the present case of cuprate superconductors the situation is different and is more complicated as we see that the pseudogap size can be larger comparable and smaller than the superconducting gap when doping increases The I-V characteristics of a superconductor-insulator-superconductor (SIS) junction can be calculated from18: where RN is junction's normal-state resistance, n(ω) is the DOS of two identical S-electrodes and f(ω) is the Fermi function. Our results were obtained by fitting the normalized experimental spectra using σ = dI/dV from equation (1) with the following normalized DOS for n(ω): Tc0) with a nonzero θp to exclude the pseudogap-dominant region on the Fermi surface By normalizing the data below Tc to the one above Tc additional structures in the measured spectra resulting from tunnel barrier phonons are successfully removed The phonon spectra extracted from the data are exactly the same as those obtained from the SIN type Pb junctions Below we further justify this approach for the present experiment by considering both the superconducting and pseudogap contributions in the fitting procedure where CS is a constant from the ungapped part on the Fermi surface The I-V curve can be calculated above Tc0 from These data show nearly the same Δs but slightly different γs where k is the energy of bare electrons relative to the value at the Fermi surface. From equation (7) it can be shown that the Green's function G(k In the ARPES experiments, it is considered to be gapped if A(kF, ω) has maxima at ω = ±ωp ≠ 0, while Fermi arc appears at places where A(kF, ω) has maximum only at ω = 0. Thus ωp can be found by setting the first derivative of equation (9) to zero: the angle θ0 at which the arc starts is found to be The relative arc length larc is defined by Scanning tunneling spectroscopy of high-temperature superconductors Coherent d-wave superconducting gap in underdoped La2–xSrxCuO4 by Angle-Resolved Photoemission Spectroscopy Phys Evolution of a pairing-induced pseudogap from the superconducting state gap of (Bi,Pb)2Sr2CuO6 Monotonic d-wave superconducting gap of the optimally doped Bi2Sr1.6La0.4CuO6 superconductor by laser-based angle-resolved photoemission spectroscopy Observation of a d-wave nodal liquid in highly underdoped Bi2Sr2CaCu2O8+δ Imaging the two gaps of the high-temperature superconductor Bi2Sr2CuO6+δ How Cooper pairs vanish approaching the Mott insulator in Bi2Sr2CaCu2O8+δ Spectroscopic fingerprint of phase-incoherent superconductivity in the underdoped Bi2Sr2CaCu2O8+δ Abrupt onset of a second energy gap at the superconducting transition of underdoped Bi2212 Coexistence of competing orders with two energy gaps in real and momentum space in the high temperature superconductor Bi2Sr2–xLaxCuO6+δ Competition between the pseudogap and superconductivity in the high-Tc copper oxides ARPES studies of cuprate Fermiology: superconductivity Disentangling Cooper-pair formation above the transition temperature from the pseudogap state in the cuprates Energy gap in superconductors measured by electron tunneling Tunneling and strong-coupling superconductivity Principles of Electron Tunneling Spectroscopy Intrinsic Josephson effects in Bi2Sr2CaCu2O8 single crystals Pseudo-gap features of intrinsic tunneling in (HgBr2)-Bi2212 single crystals 60 ns time scale short pulse interlayer tunneling spectroscopy for Bi2Sr2CaCu2O8+δ In situ measurement of self-heating in intrinsic tunneling spectroscopy Bi2Sr2CaCu2O8+δ intrinsic Josephson junctions: Surface layer characterization and control Intrinsic tunneling spectroscopy of Bi2Sr2CaCu2O8+δ: The junctionsize dependence of self-heating Observation of macroscopic quantum tunneling in a single Bi2Sr2CaCu2O8+δ surface intrinsic Josephson junction Tunneling spectra of submicron Bi2Sr2CaCu2O8+δ intrinsic Josephson junctions: evolution from superconducting gap to pseudogap Counterintuitive consequence of heating in strongly-driven intrinsic junctions of Bi2Sr2CaCu2O8+δ mesas Persistence of strong electron coupling to a narrow boson spectrum in overdoped Bi2Sr2CaCu2O8+δ tunneling data Electronic origin of the inhomogeneous pairing interaction in the high-Tc superconductor Bi2Sr2CaCu2O8+δ Direct measurement of quasiparticlelifetime broadening in a strong-coupled superconductor Strong dependence of the superconducting gap on oxygen doping from tunneling measurements on Bi2Sr2CaCu2O8–δ Phenomenology of the low-energy spectral function in high-Tc superconductors Field-enhanced diamagnetism in the pseudogap state of the cuprate Bi2Sr2CaCu2O8+δ superconductor in an intense magnetic field Specific-heat measurement of a residual superconducting state in the normal state of underdoped Bi2Sr2–xLaxCuO6+δ cuprate superconductors Enhanced superconducting gaps in the trilayer high-temperature Bi2Sr2Ca2Cu3O10+δ cuprate superconductor Modeling the Fermi arc in underdoped cuprates Gapless pairing and the Fermi arc in the cuprates Protected nodes and the collapse of Fermi arcs in high-Tc cuprate superconductors Download references This work was supported by the National Natural Science Foundation of China (Grant Nos 10974242 and 50825206) and the Ministry of Science and Technology of China (Grant No Beijing National Laboratory for Condensed Matter Physics provided and prepared single crystals for the UD71K designed the experiment and wrote the manuscript The authors declare no competing financial interests This work is licensed under a Creative Commons Attribution-NonCommercial-ShareALike 3.0 Unported License. To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/3.0/ Reprints and permissions Download citation David Hirsch, who recently led the Securities and Exchange Commission’s Crypto Assets and Cyber Unit (CACU), has joined law firm McGuireWoods as a partner in Washington Hirsch will be part of the firm’s securities enforcement and regulatory counseling practice As CACU chief in the SEC’s Division of Enforcement Hirsch oversaw first-of-their-kind investigations He was responsible for recommending and implementing the SEC’s cybersecurity enforcement priorities and played a key role in establishing the agency’s approach to enforcing registration obligations for various crypto asset activities Hirsch served as counsel to SEC Commissioner Caroline Crenshaw he reviewed and advised on enforcement recommendations before the SEC and frequently engaged with market participants Hirsch will focus on a broad securities enforcement practice including advising clients on matters related to cybersecurity and crypto assets chair of the firm’s Financial Services & Securities Enforcement Department emphasized the importance of Hirsch’s experience “Cybersecurity and crypto are rapidly evolving areas of the law and Dave’s unique background and extensive experience in securities enforcement will help our clients stay ahead of the curve.” The addition of Hirsch to McGuireWoods’ team reflects the growing demand for legal expertise in crypto and cybersecurity regulation Firms with specialized knowledge in these areas are likely to play a crucial role in helping clients navigate complex compliance challenges and enforcement actions in the space Don’t have an account? Already have an account? ' + scriptOptions._localizedStrings.webview_notification_text + ' " + scriptOptions._localizedStrings.redirect_overlay_title + " " + scriptOptions._localizedStrings.redirect_overlay_text + " is seeking members’ approval for a proposed merger with CommunityAmerica Credit Union BMCU holds about $27 million of assets and was chartered in 1971 to serve employees of Burns & McDonnel CommunityAmerica serves consumers across the Kansas City metro region and has branches on both sides of the Kansas-Missouri state line At $3.5 billion of assets it is the largest credit union in either state and the deal will add about 2,000 members to its roster and boost its assets slightly “The credit union industry has faced an unprecedented and sustained interest rate environment that has made income growth challenging Merging with CACU transitions our members to a sound financial institution with both income and capital strength,” Hassan Sahudin The credit union earned just under $100,000 in 2020 down from more than $286,000 in 2019 as expenses rose lending contracted and noninterest income declined If approved a merger into CommunityAmerica would provide Burns & McDonnell members with access to a wider array of products and services Two BMCU employees will also be retained and will be recognized with payments of $10,000 each once the deal closes BMCU members will also receive a $380,000 bonus dividend based on their average daily balance for all deposit products during 2020 The payout will be distributed at the time of the merger because CommunityAmerica only requires a minimum share balance of $1 A virtual meeting to vote is scheduled for June 8 Metrics details Strong correlation between spins and conduction electrons is key in spintronic materials and devices A few ferro- or ferrimagnetic transition metal oxides such as La1−xSrxMnO3 CrO2 and Sr2FeMoO6 have spin-polarized conduction electrons at room temperature but it is difficult to find other spin-polarized oxides with high Curie temperatures (well above room temperature) and large magnetizations for spintronics applications Here we show that an A- and B-site-ordered quadruple perovskite oxide has spin-polarized conduction electrons and is ferrimagnetic up to 560 K The couplings between the three magnetic cations lead to the high Curie temperature a large saturation magnetization of 8.7 μB and a half-metallic electronic structure in which only minority-spin bands cross the Fermi level producing highly spin-polarized conduction electrons Spin polarization is confirmed by an observed low-field magnetoresistance effect in a polycrystalline sample Optimization of CaCu3Fe2Re2O12 and related quadruple perovskite phases is expected to produce a new family of useful spintronic materials This leads to large tunnelling magnetoresistance (TMR) in a low magnetic field which can be exploited in high-performance magnetic sensors and extremely high-density memories Although a large TMR was observed in such trilayer devices at low temperatures the TMR ratio became small at room temperature because the degree of spin polarization decreases significantly near the magnetic transition temperature Materials that have highly spin-polarized conduction electrons at room temperature and hence a magnetic transition temperature well above 300 K are therefore very desirable for further spintronic developments We have explored a strategy for enhancing spintronic properties relative to double perovskites by introducing further magnetic cations that can participate in a 1:3 order at the A sites leading to the discovery of a new A- and B-site ordered quadruple perovskite oxide with large magnetization and a high magnetic ordering temperature Ca and Cu ions are ordered in a 1:3 ratio at the A sites and Fe and Re ions are ordered in a rock-salt-type arrangement on the B sites of the ABO3 perovskite structure resulting in a framework of CuO4 square units and heavily tilted FeO6 and ReO6 octahedra the calculated profile (full curve) and the difference between the observed and calculated intensities (offset curve below) are shown The ticks indicate the Bragg peak positions The inset shows an expanded view of the low-angle (1 1 1) and (2 0 0) diffraction peaks from which additional Scherrer broadening of (1 1 1) due to limited-range coherence of Fe/Re cation order is seen (a) Temperature dependence of magnetic susceptibility measured under an external field of 10 kOe, with the magnetic transition observed at 560 K. (b) Magnetization-field measurements at 5 K, revealing a large saturated magnetization of 8.7 μB f.u.−1. The low-field region is expanded in Fig. 7b (a) XAS and MCD intensities near the Cu L3 and L2-edges (b) XAS and MCD intensities near the Fe L3 and L2-edges represent XAS spectra measured with photon spins parallel (I+) and antiparallel (I−) to the magnetization direction of the sample in which a static magnetic field of 19 kOe was applied The MCD intensity was calculated as the difference between the I+ and I− absorption spectra The coincident signs of the Cu and Fe MCD intensities at each L-edge show that their spins couple ferromagnetically (a) The double-perovskite Ca2FeSbO6 with a spin-glass transition temperature of 17 K Order of antiferromagnetically interacting Fe3+ spins is frustrated due to the tetrahedral geometry of the B sublattice (b) A- and B-site-ordered quadruple perovskite CaCu3Fe2Sb2O12 with nonmagnetic Sb5+ at the B′ site and Tc=170 K A′-site Cu2+ spins couple antiferromagnetically with the B-site Fe3+ spins (c) Charge-disproportionated CaCu3Fe4O12 with Tc=210 K where A′-site Cu2+ spins couple antiferromagnetically with the B-site Fe3+ and B′-site Fe5+ spins (d) CaCu3Fe2Re2O12 where A′-site Cu2+ spins couple ferromagnetically with the B-site Fe3+ and antiferromagnetically with the B′-site Re5+ spins leading to a high Tc of 560 K and a large magnetization of 8.7 μB f.u.−1 CaCu3Fe2Re2O12 is notable among magnetic oxides in offering both a high Tc and a large saturated magnetization Calculated density of states (DOS) and band structures for up-spin and down-spin electrons Total DOS (shaded regions) and partial DOS of Cu (green curves) Re (blue curves) and O (light blue curves) are shown Only the down(minority)-spin bands cross the Fermi level (EF) as there is a gap in the up(majority)-spin bands S=1: ↓)2O12 ferrimagnetic spin structure well (a) Magnetic field dependence of resistivity measured at 10 K with external fields from −50 to 50 kOe Inset shows temperature dependence of zero-field resistivity (b) A magnified view of the field dependence of resistivity and magnetization on cycling The observed low-field spin-valve-type magnetoresistance reveals intergrain tunnelling of spin-polarized conduction carriers The new quadruple perovskite CaCu3Fe2Re2O12 synthesized by high-pressure and -temperature synthesis is cation ordered at both A and B sites and has a cubic structure with formal charge distribution Ca2+Cu2+3Fe3+2Re5+2O12 Strong antiferromagnetic coupling of Re5+ spins to those of Cu2+ and Fe3+ results in ferrimagnetic CaCu2+(↑)3Fe3+(↑)2Re5+(↓)2O12 order with a high transition temperature (560 K) and a large magnetization (8.7 μB f.u.−1) XAS-MCD and neutron diffraction measurements confirm the ferrimagnetic spin structure Electronic structure calculations predict that the ferrimagnetic ground state is half-metallic with only minority-spin bands crossing the Fermi level Resistivity measurements confirm spin-polarized conduction and a low-field spin-valve-type magnetoresistance is evident although further optimization to suppress Fe/Re disorder fully is needed The combination of a high magnetic ordering temperature and large magnetization in comparison to double-perovskite analogues and spin-polarized conductivity demonstrates that the introduction of further magnetic cations that can participate in a 1:3 order at the A sites is a good strategy for discovery of a new family of spintronic quadruple perovskite oxide materials A polycrystalline sample of CaCu3Fe2Re2O12 was prepared by a solid-state reaction at a high temperature and high pressure ReO3 and Fe2O3 were well mixed and the mixture was sealed in a platinum capsule The assembled sample cell was placed in a DIA-type cubic anvil high-pressure apparatus and treated at 10 GPa and 1400 K for an hour A SXRD experiment was carried out for phase identification and crystal structure analysis The room-temperature SXRD pattern obtained with a wavelength of 0.498856 Å was recorded on the image plate of a large Debye–Scherrer camera installed at beamline BL02B2 in SPring-8 The powder sample was placed in a 0.1 mm glass capillary tube to minimize absorption and rotated during the measurement The obtained data were analysed with the Rietveld method by using the TOPAS software package Magnetic properties were measured with a commercial magnetometer (Quantum Design Magnetic Properties Measurement System) Temperature dependence of the magnetic susceptibility was measured at 5–700 K in an external magnetic field of 10 kOe Field dependence of the magnetization was measured at several temperatures under fields ranging from −50 to 50 kOe X-ray MCD spectra were obtained by a total electron yield method from X-ray absorption experiments conducted at beamline BL25SU in SPring-8 The powder sample was pasted uniformly on a sample holder by using carbon tape The spectra at 15 K were obtained using parallel (I+) and antiparallel (I-) photon spins along the magnetization direction of the sample to which a static magnetic field of 19 kOe was applied The MCD intensity was defined as the difference between the two absorption spectra (IMCD=I-−I+) Transport properties of the sample were measured in a conventional four-probe configuration The temperature dependence of the resistivity and magnetoresistance were measured under magnetic fields ranging from −50 to 50 kOe The electronic structure of CaCu3Fe2Re2O12 was calculated by full-potential linearized augmented plane-wave first-principle calculations with the WIEN2k code The lattice constant and atomic position parameters obtained from the structural refinement were used for the calculation The full-potential linearized augmented plane-wave sphere radii for Ca An effective Ueff (=U−J) of 4 eV was introduced for B-site Fe and B′-site Re Self-consistency was carried out on 1000 k-point meshes in the whole Brillouin zone Fe/Re inversion was not refined as these two elements have very similar nuclear scattering factors; b(Fe)=9.5 fm and b(Re)=9.2 fm A half-metallic A- and B-site-ordered quadruple perovskite oxide CaCu3Fe2Re2O12 with large magnetization and a high transition temperature Polarized electron probes of magnetic surfaces New class of materials: half-metallic ferromagnets CrO2 predicted as a half-metallic ferromagnet Observation of vacuum tunneling of spin-polarized electrons with the scanning tunneling microscope Band structure in the high temperature phase of Fe3O4 Progress towards spin-polarized scanning tunneling microscopy Giant magnetotransoprt phenomena in filling-controlled Kondo lattice system: La1−xSrxMnO3 Thousandfold change in resistivity in magnetoresistive La-Ca-Mn-O films Giant magnetoresistance in Tl2Mn2O7 with the pyrochlore structure Ferromagnetic compounds of manganese with perovskite structure Interaction between the d-shells in the transition metals Effects of double exchange in magnetic crystals Electronic structure and half-metallic transport in the La1−xCaxMnO3 system Direct evidence for a half-metallic ferromagnet Observation of large low-field magnetoresistance in trilayer perpendicular transport devices made using doped manganate perovskites Low-field colossal magnetoresistance in manganite tunnel spin valves Tunneling magnetoresistance at up to 270 K in La0.8Sr0.2MnO3/SrTiO3/La0.8Sr0.2MnO3 junctions with 1.6-nm-thick barriers B-cation arrangements in double perovskites Ordered double perovskites—a group-theoretical analysis Double perovskites with ferromagnetism above room temperature Room-temperature magnetoresistance in an oxide material with an ordered double-perovskite structure Theory of half-metallic double perovskites Effective spin Hamiltonian and disorder effects New functional materials AC3B4O12 (Review) A-site-ordered perovskites with intriguing physical properties Ferromagnetic cuprates CaCu3Ge4O12 and CaCu3Sn4O12 with A-site ordered perovskite structure Unusual ferromagnetic-to-antiferromagnetic-to-ferromagnetic transitions in Cu2+ (S=1/2) cubic spin lattice of A-site ordered perovskites Large low-field magnetoresistance in perovskite-type CaCu3Mn4O12 without double exchange Enhanced magnetoresistance in the complex perovskite LaCu3Mn4O12 Magnetoresistance and electronic structure of the half-metallic ferrimagnet BiCu3Mn4O12 New ferrimagnetic oxide CaCu3Cr2Sb2O12: high-pressure synthesis Frustration relieved ferrimagnetism in novel A- and B-site-ordered quadruple perovskite New perovskite oxide CaCu3Cr2Ru2O12: comparison with structural and transport properties of the CaCu3B2B’2O12 perovskite family Bond-valence parameters obtained from a systematic analysis of the Inorganic Crystal Structure Database A perovskite containing quadrivalent iron as a charge-disproportionated ferrimagnet Magnetic coupling between A’ and B sites in the A-site-ordered perovskite BiCu3Mn4O12 Controlled-valence properties of La1−xSrxFeO3 and La1−xSrxMnO3 studied by soft-X-ray absorption spectroscopy X-ray circular dichroism as a probe of orbital magnetization X-ray circular dichroism and local magnetic fields Investigation of magnetic frustration in A2FeMO6 (A=Ca Sb) by magnetometry and Mössbauer spectroscopy Direct observation of the ferrimagnetic coupling of A-site Cu and B-site Fe spins in charge-disproportionated CaCu3Fe4O12 Properties of the ferrimagnetic double perovskites A2FeReO6 (A=Ba and Ca) Ferromagnetic resonance and magnetization studies on ferrimagnetic double perovskites A2FeReO6 (A=Ca Impact of cation size on magnetic properties of (AA’)2FeReO6 double perovskites Electronic structure study of double perovskites A2FeReO6 (A=Ba Structural and magnetic properties of (Sr2-xCax)FeReO6 High-field magnetization measurements in Sr2CrReO6 double perovskite: evidence for orbital contribution to the magnetization Sr2CrOsO6: end point of a spin-polarized metal-insulator transition by 5d band filling Strong electron correlation of Re 5d electrons in Ca2FeReO6 Spin-polarized intergrain tunneling in La2/3Sr1/3MnO3 Intergranular magnetoresistance in Sr2FeMoO6 from a magnetic tunnel barrier mechanism across grain boundaries Download references Tsuji for their help with the SXRD measurements at BL02B2 in SPring-8 Oguchi for fruitful discussion on the electronic structure calculations The SPring-8 experiments were performed with the approval of the Japan Synchrotron Radiation Research Institute (proposal nos: 2012A1006 and 2013B1011) This work was supported by Grants-in-Aid for Scientific Research (nos: 19GS0207 and 22740227) by a grant for the Joint Project of Chemical Synthesis Core Research Institutions from MEXT and by a JST-CREST program of Japan Part of the work was performed under the Strategic Japanese-UK Cooperative Program by JST and ESPRC and under the young researchers exchange program of ICR Present address: Present address: Center for Condensed Matter Sciences Present address: Present address: Diamond Light Source Ltd. Japan Synchrotron Radiation Research Institute Centre for Science at Extreme Conditions and School of Chemistry prepared the sample and measured the structural and physical properties All of the authors contributed to the interpretation and discussion of the experimental results Supplementary Figure 1 and Supplementary Table 1 (PDF 35 kb) Download citation — One man died after two suspects reportedly shot at each other after a dispute outside of a Community America Credit Union in Kansas City KCK police were called to the bank at 78th & State Avenue at about 11:00 Saturday morning after a dispute which began inside of a City Gear Two suspects reportedly got in an argument As the suspects then began to leave the area one vehicle struck a man who was not connected to the dispute in his late 50's or early 60's suffered critical injuries Report a typo Metrics details A highly efficient third generation catalyst CaCu3Ti4O12 (CCTO) shows excellent photoelectrochemical (PEC) and photocatalytic ability As only 4% part of the solar spectrum covers UV light thus it is highly desirable to develop visible light active photocatalyst materials like CCTO for effective solar energy conversion A direct band transition with a narrow band gap (1.5 eV) was observed high photocurrent density was found to be 0.96 mA/cm2 indicating the visible light induced photocatalytic ability of CCTO Visible light mediated photocatalytic and photoelectrocatalytic degradation efficiency of CaCu3Ti4O12 pellets (CCTO) was investigated for three classes of pharmaceutical waste: erythrosin (dye) ciprofloxacin (antibiotic) and estriol (steroid) It is found that the degradation process follows first order kinetic reaction in electrocatalysis photocatalysis and photoelectrocatalysis and high kinetic rate constant was observed in photoelectrocatalysis This was quite high in comparison to previously reported methods Thus alternative cost-effective techniques are highly required to degrade this environmental discharge of pharmaceuticals and hazardous dyes A PEC cell provides a sustainable process to transform solar energy into chemical fuel and electricity This is a highly efficient operation can be triggered simply by sunlight PEC water splitting is the most direct mechanism which can be used for hydrogen generation solar energy harvesting and waste water treatment Water splitting is an endergonic process requiring an energy input of 237 kJ/mol of water Solar light can be an efficient source for the necessary energy input that energy needs to be efficiently collected through absorption processes and transferred into a water molecule to break its chemical bonds Photoelectrochemical splitting of water into oxygen and hydrogen has emerged as a potentially viable option for the efficient degradation of pollutants we demonstrate the visible light induced photoelectrochemical behavior and photocatalytic activity of CCTO ceramic for the three different classes of pharmaceuticals: dyes this is the first report for the enhanced visible light photocatalytic activity of CCTO ceramic pellets for the pharmaceutical pollutants X-ray diffraction patterns of (i) as prepared CaCu3Ti4O12 (CCTO) (ii) CCTO pellets sintered at 1130 oC/2 h and (iii) ICDD data file card no (b) Scanning electron micrographs of the CCTO pellets sintered at 1130 °C/2 h (a) UV-Vis Absorbance spectrum of the CCTO (b) plot between Kubelka-munk function (F(R) hʋ)2 and photon energy (hʋ) shows direct allowed transition (a) Change in absorbance of Erythrosine (525 nm) (b) Color change in erythrosine under dark and light (Figure drawn by author H.S Kushwaha) (c) Change in absorbance of Ciprofloxacin (276 nm) and (d) fluorescence emission of estriol (305 nm excited at 240 nm) with time in photocatalytic degradation using CCTO pellets under visible light (λ>420 nm) The degradation efficiency (D %) of CCTO pellets for the pollutants is calculated using (b) first order kinetic decay plots for the visible light catalysis of erythrosine (c) Degradation rate (%) in different photocatalytic cycle constant degradation rate was observed which attributed as stability and reusability of the catalyst Mass spectra of (a) the erythrosine solution before photocatalysis (b) after 30 minutes photocatalysis with CCTO pellet under visible light (a) PEC studies of CCTO in 1 M L−1 KOH under visible light illumination and in the dark Nd = electron donor density,Va = applied potential and Vfb = flat band potential CCTO electrode exhibits Rct (2.8 kΩ) indicating the more favorable environment for hole transfer to the electrolyte Cyclic voltammogram for (a) electrocatalysis (b) photoelectrocatalysis of erythrosine solution (The arrows in figure show the change in the peak current for the oxidation for pollutants) and (c) First order kinetic decay plots for the electrocatalysis and photoelectrocatalysis of erythrosine The photocatalytic performance of catalyst is depends upon its light absorption ability and electron transfer ability The process starts only when the incident light energy is equal to or larger than band gap CCTO photocatalyst is a novel material for visible light catalysis due to its high absorbance spectrum narrow band gap and ability to transfer the photogenerated charge carriers The process followed by the direct oxidation of pharmaceuticals by photo generated hydroxyl radicals and holes The indirect oxidation is performed by the ˙OH radials generated by water splitting a novel visible light active CaCu3Ti4O12 ceramic was synthesized from the oxalate precursor route CCTO have broad absorbance spectrum for visible light and narrow band gap which makes it a potential material for visible light induced photocatalysis and photoelectrochemical cell CCTO pellet electrodes show high photocurrent density 0.97 mA/cm2 It shows the potential of CCTO photoanode for the high performance PEC solar cells for energy conversion CCTO ceramic pellets have more efficient photocatalytic ability to degrade erythrosine ciprofloxacin and estriol than any other catalyst under visible light The catalysis was performed by using CCTO pellets and does not require any additional filtration process to remove the catalyst which is an added advantage over the catalysis in powder form This study has demonstrated fabrication of third generation photocatalyst with two distinct transition metals for the visible light mediated photoelectrochemical and photocatalytic degradation for three different classes of pharmaceutical water pollutants which can be applied to develop new class of visible light active catalysts for other pollutants the titania gel was prepared from the aqueous TiOCl2 (0.05 M) by adding NH4OH at room temperature till the pH reaches ~8.0 and washed with water to remove NH4Cl Synthesized titania gel was powdered and dissolved in H2C2O4.2H2O The solution remained clear without any precipitate formation Cupric chloride solution in acetone and water (80:20) was added slowly and stirred continuously at 10 °C washed several times with acetone to make it chloride-free and dried in air The precipitate thus prepared was isothermally heated above 680 °C to get the ceramic powders of CaCu3Ti4O12 The resultant powder was ground thoroughly ball milled for 2 h and granulated by adding polyvinyl alcohol (PVA) and poly ethylene glycol (PEG) then pressed into pellets at 150 MPa with a diameter of 12 mm and thickness of 2 mm The green pressed pellets were slowly heated to 600 °C to get rid of the binder the pellets were sintered in air at 1130 °C for 2 h Pellet densities were measured by the Archimedes principle using xylene as the liquid medium X-ray powder diffraction studies were carried with an X’pert diffractometer (Philips Netherlands) using Cu Kα1 radiation (λ = 0.154056 nm) in a wide range of 2θ (10o–90o) with 0.02 step size to examine the phase constitutes of the specimens Scanning electron microscope (FEI-Technai SEM-Sirion) was used to observe the microstructure of the sintered pellets Optical properties of CCTO powder were analyzed by UV-vis absorbance spectroscopy Autolab) was used to perform cyclic voltammetry and electrochemical impedance studies in a three-electrode photoelectrochemical cell with CCTO pellet as the working electrode a platinum wire as the counter electrode and 1M L−1 KOH as electrolyte a copper wire was attached with the silver paste at side of pellet and sealed with epoxy to avoid the copper contact with electrolyte Cyclic voltammetry and Linear Sweep Voltammetry (LSV) scan were performed between −1 V to 0.5 V vs PEC cell was assembled using a CCTO pellet electrode with an area of 1 cm2 as a photoanode Pt wire as a counter electrode and 1 M L−1 KOH as electrolyte A halogen lamp with a power of 100 mW/cm2 was used as the incident light source and placed at 10 cm distance from the electrochemical cell Pharmaceutical dye erythrosine, antibiotic ciprofloxacin and estriol were used to test the photocatalytic activity of sintered CCTO pellets. Table 1 shows the chemical structures applications and toxicological effect of pollutants which are used for photocatalytic degradation in this paper The photocatalytic degradation experiments was carried out by using 10 ml solution of10 mg/L ciprofloxacin 10 mg/L erythrosine and 1 mg/L of estriol in deionized water A total of 10 ml solution of pharmaceutical compound was transferred in pyrex glass vessel and the sintered CCTO pellet was placed vertically in vessel The vessel was kept in dark for 30 min to allow stabilization and pre adsorption of pharmaceutical species on catalyst pellet The photocatalytic degradation process was initiated by exposing the reaction vessel with visible light 150 W halogen lamp with UV-light cutoff filter (λ>420 nm) cold water was circulated around the vessel to maintain at room temperature Sample aliquots of pharmaceuticals were collected at various time intervals and analyzed for change in concentration The concentration of erythrosine and ciprofloxacin were analyzed using Shimadzu-2450 UV-vis spectrophotometer by measuring the peak intensity The degradation of estriol was investigated by fluorescence spectrophotometer The analysis was performed using 3 ml of sample aliquots High resolution mass spectroscopy analysis was performed to analyze the subsequent species produced during photocatalytic degradation of erythrosine Photoelectrocatalytic degradation of erythrosine was carried out in a single photoelectrochemical compartment The CCTO photoanode (12 mm diameter and 1 mm thickness) and a platinum wire cathode were placed in parallel in a cuboid glass reactor (volume of 100 mL) with a SCE reference electrode All electrodes were connected to a Metrohom A halogen lamp placed outside the glass reactor and paralleled to the CCTO photoanode A bias potential applied on the CCTO photoanode was varied from 0.5 V to 1.5 V (vs SCE) under visible light intensity of 100 mW cm−2 All the experiments were performed at room temperature (about 25 °C) with a magnetic stirrer at a constant speed Efficient Solar Energy Conversion Using CaCu3Ti4O12 Photoanode for Photocatalysis and Photoelectrocatalysis Removal of residual pharmaceuticals from aqueous systems by advanced oxidation processes Removing pharmaceuticals and endocrine‐disrupting compounds from wastewater by photocatalysis Photocatalytic degradation of various types of dyes (Alizarin S Methylene Blue) in water by UV-irradiated titania Electrochemical photolysis of water at a semiconductor electrode Pharmaceuticals and personal care products in the environment: agents of subtle change Bulletin of Environmental Contamination and Toxicology 51 Pharmaceuticals: a threat to drinking water Human pharmaceuticals in the aquatic environment: a challenge to green chemistry Pharmaceuticals as emerging contaminants and their removal from water fate and effects of pharmaceutical substances in the environment-A review Antibiotics and antibiotic resistance in water environments Lifetime toxicity/carcinogenicity study of FD & C Red No Lifetime toxicity/carcinogenicity studies of FD & C Blue No Water purification by semiconductor photocatalysis Removal of toxic metal ions from wastewater by semiconductor photocatalysis Semiconductor-based photocatalytic hydrogen generation Visible light photocatalysis in transition metal incorporated titania-silica aerogels Visible-light-response and photocatalytic activities of TiO2 and SrTiO3 photocatalysts codoped with antimony and chromium Visible-light photocatalysis in nitrogen-doped titanium oxides Visible light water splitting using dye-sensitized oxide semiconductors Enhancement of photocatalytic H2 evolution on CdS by loading MoS2 as cocatalyst under visible light irradiation a Visible-Light-Sensitive Photoactive Material of Third Generation ABO3-based photocatalysts for water splitting Combinatorial discovery of visible-light driven photocatalysts based on the ABO3-type (A= Y conductivity and dielectric properties investigation of A3 CoNb2 O9(A = Ca2+ ACu3 Ti4 O12 and ACu3 Ru4 O12 perovskites: high dielectric constants and valence degeneracy Synthesis of nanoparticles of the giant dielectric material Ferroelectriclike and pyroelectric behavior of CaCu 3 Ti 4 O 12 ceramics Molten Salt Synthesis of Nanocrystalline Phase of High Dielectric Constant Material CaCu3Ti4O12 Effect of calcium stoichiometry on the dielectric response of CaCu3 Ti4 O12 ceramics Visible light photo-oxidation of model pollutants using CaCu3Ti4O12: an experimental and theoretical study of optical properties Adsorption and photocatalytic decolorization of a synthetic dye erythrosine on anatase TiO2 and ZnO surfaces Highly sensitive and accurate screening of 40 dyes in soft drinks by liquid chromatography–electrospray tandem mass spectrometry Removal of the antibiotic levofloxacin (LEVO) in water by ozonation and TiO2 photocatalysis FeCl3/NaNO2: an efficient photocatalyst for the degradation of aquatic steroid estrogens under natural light irradiation Selective degradation of ciprofloxacin with modified NaCl/TiO2 photocatalyst by surface molecular imprinted technology Characterization of methyl orange and its photocatalytic degradation products by HPLC/UV–VIS diode array and atmospheric pressure ionization quadrupole ion trap mass spectrometry Study on the photocatalytic degradation of methyl orange in water using Ag/ZnO as catalyst by liquid chromatography electrospray ionization ion-trap mass spectrometry Photocatalytic degradation pathway of methylene blue in water Preliminary ecotoxicological evaluation of erythrosin b and its photocatalytic degradation products Kinetics and mechanism of advanced oxidation processes (AOPs) in degradation of ciprofloxacin in water Visible-light-mediated TiO2 photocatalysis of fluoroquinolone antibacterial agents Photocatalytic oxidation of multicomponent mixtures of estrogens (estrone (E1) 17α-ethynylestradiol (EE2) and estriol (E3)) under UVA and UVC radiation: photon absorption quantum yields and rate constants independent of photon absorption TiO2 microcrystallized glass plate mediated photocatalytic degradation of estrogenic pollutant in water Direct and indirect photodegradation of estriol in the presence of humic acid nitrate and iron complexes in water solutions Heterogeneous photocatalytic degradation of organic contaminants over titanium dioxide: a review of fundamentals Download references The authors would like to extend their sincere appreciation to the Deanship of Scientific Research at Kind Saud University for funding this research group no preformed the sample characterization measurements and analyzed all the results were involved in the design of experiments editing of the manuscript and discussions throughout the work Download citation Environmental Science and Pollution Research (2023) Environmental Science and Pollution Research (2022) Metrics details Prices may be subject to local taxes which are calculated during checkout Emergence of preformed Cooper pairs from the doped Mott insulating state in Bi2Sr2CaCu2O8+δ Evidence for pairing above the transition temperature of cuprate superconductors from the electronic dispersion in the pseudogap phase Visualizing pair formation on the atomic scale in the high-Tc superconductor Bi2Sr2CaCu2O8+δ Neutron scattering as a probe for unconventional superconducting states Theory of neutron scattering in the normal and superconducting states of YBa2Cu3O6+x Neutron scattering from a collective spin fluctuation mode in a CuO2 bilayer Evolution of the bosonic spectral density of the high-temperature superconductor Bi2Sr2CaCu2O8+δ The effect of collective spin-1 excitations on electronic spectra in high-Tc superconductors Neutron scattering from magnetic excitations in Bi2Sr2CaCu2O8+δ Odd and even magnetic resonant modes in highly overdoped Bi2Sr2CaCu2O8+δ Dispersion of the odd magnetic resonant mode in near-optimally doped Bi2Sr2CaCu2O8+δ Quantum magnetic excitations from stripes in copper oxide superconductors Energy gaps in the failed high-Tc superconductor La1.875Ba0.125CuO4 Spin susceptibility of underdoped cuprate superconductors: Insights from a stripe-ordered crystal Large Bi-2212 single crystal growth by the floating-zone technique Magnetic neutron scattering in hole-doped cuprate superconductors From incommensurate to dispersive spin-fluctuations: The high-energy inelastic spectrum in superconducting YBa2Cu3O6.5 Dispersion of magnetic excitations in optimally doped superconducting YBa2Cu3O6.95 Local-moment fluctuations in the optimally doped high-Tc superconductor YBa2Cu3O6.95 Magnetic fluctuations in n-type high-Tc superconductors reveal breakdown of fermiology: Experiments and Fermi-liquid/RPA calculations Magnetic energy change available to superconducting condensation in optimally doped YBa2Cu3O6.95 Two energy scales in the spin excitations of the high-temperature superconductor La2−xSrxCuO4 and fluctuations in La1.875Ba0.125CuO4 and La1.875Ba0.075Sr0.050CuO4 Two-dimensional superconducting fluctuations in stripe-ordered La1.875Ba0.125CuO4 Neutron-scattering study of antiferromagnetism in YBa2Cu3O6.15 Spherical neutron polarization analysis on the three-axis spectrometer IN22 Download references We gratefully acknowledge assistance from C and a critical reading of the manuscript by S This work was supported by the Office of Science Download citation Share on FacebookShare on X (formerly Twitter)Share on PinterestShare on LinkedInCLAY COUNTY (KCTV) - The FBI is investigating an armed robbery that happened Wednesday at a bank in Pleasant Valley Authorities said it happened Wednesday at approximately noon at the Community America Credit Union at 8100 N A suspect was identified as an unknown male 150 pounds wearing a track-style jacket with a hood The man was wearing blue jeans and had a full face covering with aviator-style sunglasses Authorities said the suspect displayed a weapon and made a demand for money during the robbery He fled the bank with an undisclosed amount of money heading westbound toward Interstate 435 You are using an outdated browser. Please upgrade your browser to improve your experience “What’s happening a lot in the world today is all this reverse mentoring,” said Newton, chief innovation officer at CommunityAmerica Credit Union “Young people are teaching the older people how to consume media and use tools.” CommunityAmerica plans to hire about 20 high school students from Johnson County for the credit union’s first annual Teen Advisory Innovation Board “Teens are perfect for innovation because they are incredibly tech savvy and have grown up with these tools,” said Newton, who is also the co-founder of the Mighty Handle device “We’re looking for students who are articulate Selected teens will meet a couple hours per month from January to June 2018 and will be compensated $200 dollars for their time Interns will also witness every step of the innovation process prototyping and bringing a product to market with measurements “We tried to maximize the amount of learning with a minimal amount of time because we know teens are busy,” she said “They’ll get to meet teenagers from around a bunch of schools which is great if they could meet other people that are like-minded and curious and interesting that’s another benefit.” Students attending Shawnee Mission, Blue Valley and Olathe School Districts are eligible to apply until Nov. 30. The application is expected to take about 30 minutes and asks students to submit a short video sharing one thing they like about their favorite social media application three things they would change about it and why Newton is confident that the program will have mutual benefit for both the students and the credit union “I don’t know how you can succeed as a seasoned entrepreneur without very direct mentorship from young people,” Newton said “I have young digital natives that I call on frequently when I have questions.” Newton hopes students also will help shape the pilot program itself by sharing what worked and what didn’t CommunityAmerica plans to expand to Jackson County In June, CommuityAmerica launched its Innovation Lab with Newton The lab is focused on creating tools for the credit union’s members that will help them plan for college get married or deal with the launch of a family member Newton spent her first month on the job interviewing members to discover their needs “The role of a bank is evolving,” Newton said “(The Innovation Lab is) looking at all the things that keep our members up at night and figuring out how can we address them we are looking at how to digitize these things CommunityAmerica is the largest credit union in the Kansas City area 27 branches and manages more than $2 billion in assets To apply for the Teen Advisory Innovation board, click here. The National Water Commission’s (NWC) team walked away with the Consumer Advisory Committee on Utilities’ (CACU) inaugural Utility Customer Service Distinction Award on November 28 during the Office of Utilities Regulation’s (OUR) seventh Quality of Service (QoS) Symposium The CACU’s award was launched to acknowledge and recognise excellence in customer service by utility staff who establish and maintain a positive and effective working relationship with internal/external customers NWC’s corporate public relations manager (acting) noted that the winner was identified by their colleagues and/or customers as being dedicated to continuously improving customer satisfaction and reacting appropriately to ensure customer satisfaction demonstrated excellence in resolving customer complaints and/or challenges presented by utility consumers CACU’s criteria for selecting the award winner included: a positive attitude that has a positive impact on the internal/external customer experience; delivering exceptional service above and beyond the call of duty and consistently striving to eliminate barriers for customers by effectively and efficiently communicating Employees of the Jamaica Public Service Company Ltd The OUR has moved to improve the quality of customer care that utility entities provide for their customers via the annual QoS Symposia which are consultative forums with customer service management and officers of all utility providers the OUR has developed guidelines for complaint handling and standards for customer service to assist the utilities in managing quality and service excellence executive chairman of Market Research Services Ltd was the guest speaker View the discussion thread. UBUTUNZI BWO MW’IJAMBO RY’IMANA | 2 ABAKORINTO 7-10 8:1-4; 9:7 Tuba dufashije abavukanyi bacu kuronka ivyo bakeneye.—2Kr 9:12a Tuba dufashije abari mu ngorane gusubirana urutonde rwabo rwo mu vy’impwemu, nko kwamamaza inkuru nziza n’umwete kugira berekane ko bakengurukira Yehova.—2Kr 9:12b Turatuma Yehova aninahazwa. (2Kr 9:13) Igikorwa cacu co gutabara kirashinga intahe ku bantu bose ushizemwo n’abiyumvira Ivyabona vya Yehova uko batari Abasoda bariko bapfindanira impuzu za Yezu Yezu yobaye nk’uwuhebwe n’Imana (Zb 22:1; w11 15/8 15 ing Yezu yotutswe (Zb 22:7, 8; w11 15/8 15 ing Ivyambarwa vya Yezu bobipfindiye (Zb 22:18; w11 15/8 15 ing NIWIBAZE UTI: “Ni gute Zaburi ya 22 ituma ndushiriza kwizigira ko n’ubundi buhanuzi bwerekeye Mesiya, nka Mika 4:4 Zb 22:22—Ni mu buryo bubiri ubuhe twokwigana uwo mwanditsi wa Zaburi muri iki gihe Ni ibiki wize mu gisomwa ca Bibiliya c’ino ndwi (Imin. 4) Zb 22:1-19 (th icigwa ca 2) (Imin. 3) INZU KU NZU. (lmd icigwa ca 4 iciyumviro ca 4) (Imin. 4) AKARYO KIZANYE. Nusubire kuyaga n’umuntu muzinanye yemeye ubutumire bw’Icibutso wamuhaye. (lmd icigwa ca 4 iciyumviro ca 3) (Imin. 5) w20.07 12-13 ing. 14-17—Umutwe: Ingene ubuhanuzi bwo muri Bibiliya bukomeza ukwizera. (th icigwa ca 20) View the discussion thread. "This misplaced focus on electricity market liberalisation carries with it the danger of destabilising and delaying the actions that have real promise of bringing lower electricity prices to Jamaica," the CACU said in a statement whose acting chairman is Stephen Wedderburn the most important issues to be addressed in achieving reduced electricity prices "are the introduction of an alternative fuel to oil and the installation of new the loss of JPS's exclusivity would threaten the successful implementation of the long-awaited LNG project and the installation of the new and efficient 360 MW combined-cycle plant." JPS is slated to construct the 360mw liquefied petroleum gas plant at Old Harbour it means that Jamaica will spend even more years with high electricity prices as there are no other projects on the horizon that could lead to a significant reduction in electricity rates," the CACU said It added that market liberalisation by itself would not lead to lower electricity prices The eight-member advisory committee was established by the Office of Utilities Regulation (OUR) in 2000 It comprises an independent group of persons from the public who provide the OUR with a forum through which its receives consumers' views on broad regulatory issues as well as perspectives on issues which affect the relationship between utility companies and consumers Part of its mandate is to report to the OUR on matters pertaining to the provision of utility services which affect the interests of consumers Members of the committee include Yasmin Chong Justice Bryan Sykes issued a landmark ruling that the exclusivity provisions in the all-island electric licence granted to the JPS were invalid on the basis that the relevant minister does not have the requisite authority to grant a licence on terms that bar the possibility of any other person entering the market for the transmission of electricity The ruling has been accepted in some quarters as signalling the end of JPS' monopoly in the transmission and distribution of electricity said it "does not share this sense of euphoria at Justice Sykes' ruling The committee believes that the ruling has served to introduce major uncertainties in the Jamaican electricity sector at a very critical time and could very well have the effect of significantly delaying the realisation of lower electricity prices in Jamaica." It continued: "We believe that the victory claimed by those who brought the case against JPS is likely to be a pyrrhic victory resulting in no real benefit for Jamaican consumers." CACU observed that it may seem strange that a consumer advocacy group appeared to be siding with an "unpopular monopoly provider of electricity" but its view was that Jamaica should now be giving maximum focus to those actions which would lead to lower electricity prices "We do not believe that a break-up of JPS' monopoly status will lead to lower electricity prices - at least not for the majority of electricity consumers in Jamaica - and we believe the focus on trying to liberalise the grid is distracting the society away from those concrete actions that will lead to lower electricity prices," the statement said The CACU said that as a consumer advocacy group "We believe that the path to lower electricity prices must be the main focus and that regardless of whether the transmission grid is liberalised or not Jamaica will not get lower prices until we introduce an alternative fuel to oil and install new and more efficient generation plans to replace the near obsolete steam turbine units that form a major part of Jamaica's baseload electricity generation capacity." The group said Jamaica's continued dependence on oil for electricity generation was a greater contributor to high electricity prices than whether the market was liberalised or not "Liberalising the transmission grid and having additional players generate electricity with oil is not going to give us lower electricity prices," the CACU said It also observed that electricity costs could not be reduced until critical decisions were taken and measures implemented to replace old and inefficient generating plants with more modern and efficient units "The Government has taken unto itself responsibility for both sets of measures it is the Government that sets the timetable for new generation capacity and issues the tenders for this capacity and it is well known that it is the Government which is spearheading the LNG project," the group said it noted that "there seems to be a generally accepted assumption that a liberalised electricity market will automatically lead to lower prices "We are concerned that commentators on the matter are not seeking to educate the public that in a liberalised market there is a risk that prices could very well go up "The objective of any investor is to maximise returns JPS and any other power producer will be seeking to maximise their returns and if they have the opportunity to increase prices they will not hesitate to do so," the group said referencing the liberalisation of the petroleum sector which The CACU also noted that should a decision be made to liberalise electricity transmission and distribution be able to attract enough players to sustain a truly competitive market we would likely end up with a handful of electricity generators resulting in an oligopoly structure." with approximately half a million electricity customers We believe [it is] far too small to sustain a liberalised electricity market." business@gleanerjm.com View the discussion thread.