Exotic quantum phenomena may appear in material systems with multiple orders or phases,where the mutual interactions can give rise to new physics beyond that of each component.Here,we report spectroscopic evidence for...Exotic quantum phenomena may appear in material systems with multiple orders or phases,where the mutual interactions can give rise to new physics beyond that of each component.Here,we report spectroscopic evidence for a unique combination of topology and correlation effects in the kagome superconductor CsV_(3)Sb_(5).Topologically nontrivial surface states are observed near the Fermi energy(E_(F)),indicating that the topological physics may be active upon entering the superconducting state.Flat bands are observed,suggesting that electron correlation effects are also at play in this system.Our results reveal the peculiar electronic structure of CsV_(3)Sb_(5),which holds the potential for realizing Majorana zero modes and anomalous superconducting states in kagome lattices.They also establish CsV_(3)Sb_(5)as a unique platform for exploring the interactions between the charge order,topology,correlation effects and superconductivity.展开更多
The effect of an applied magnetic field on an inhomogeneous superconductor is studied and the value of the upper critical magnetic field Hc3 at which superconductivity can nucleate is estimated. In addition, the autho...The effect of an applied magnetic field on an inhomogeneous superconductor is studied and the value of the upper critical magnetic field Hc3 at which superconductivity can nucleate is estimated. In addition, the authors locate the concentration of the order parameter, which depends on the inhomogeneous term a(x). Unlikely to the homogeneous case, the order parameter may concentrate in the interior of the superconducting material, due to the influence of the inhomogeneous term a(x).展开更多
Vacancies are prevalent and versatile in solid-state physics and materials science.The role of vacancies in strongly correlated materials,however,remains uncultivated until now.Here,we report the discovery of an unpre...Vacancies are prevalent and versatile in solid-state physics and materials science.The role of vacancies in strongly correlated materials,however,remains uncultivated until now.Here,we report the discovery of an unprecedented vacancy state forming an extended buckled-honeycomb-vacancy(BHV)ordering in Ir16Sb18.Superconductivity emerges by suppressing the BHV ordering through squeezing of extra Ir atoms into the vacancies or isovalent Rh substitution.The phase diagram on vacancy ordering reveals the superconductivity competes with the BHV ordering.Further theoretical calculations suggest that this ordering originates from a synergistic effect of the vacancy formation energy and Fermi surface nesting with a wave vector of(1/3,1/3,0).The buckled structure breaks the crystal inversion symmetry and can mostly suppress the density of states near the Fermi level.The peculiarities of BHV ordering highlight the importance of"correlated vacancies"and may serve as a paradigm for exploring other non-trivial excitations and quantum criticality.展开更多
基金supported by the Fundamental Research Funds for the Central Universities(WK3510000012 and WK3510000008)USTC Start-up Fund and National Natural Science Foundation of China(12004363)+6 种基金supported by the Swiss National Science Foundation(200021-188413)the SinoSwiss Science and Technology Cooperation(IZLCZ2-170075)supported via the UC Santa Barbara NSF Quantum Foundry funded via the Q-AMASE-i Program under award DMR-1906325the shared facilities of the NSF Materials Research Science and Engineering Center at UC Santa Barbara(DMR-1720256)supported by NSF CNS-1725797 and NSF DMR-1720256support from the California NanoSystems Institute through the Elings Fellowship programsupported by the National Science Foundation Graduate Research Fellowship Program(DGE-1650114)。
文摘Exotic quantum phenomena may appear in material systems with multiple orders or phases,where the mutual interactions can give rise to new physics beyond that of each component.Here,we report spectroscopic evidence for a unique combination of topology and correlation effects in the kagome superconductor CsV_(3)Sb_(5).Topologically nontrivial surface states are observed near the Fermi energy(E_(F)),indicating that the topological physics may be active upon entering the superconducting state.Flat bands are observed,suggesting that electron correlation effects are also at play in this system.Our results reveal the peculiar electronic structure of CsV_(3)Sb_(5),which holds the potential for realizing Majorana zero modes and anomalous superconducting states in kagome lattices.They also establish CsV_(3)Sb_(5)as a unique platform for exploring the interactions between the charge order,topology,correlation effects and superconductivity.
基金Project supported by the National Natural Science Foundation of China (No.10071067) the Excellent Young Teachers Program of the Ministry of Education of China, the Jiangsu Provincial Natural Science Foundation of China and the Combinatorial and Computa
文摘The effect of an applied magnetic field on an inhomogeneous superconductor is studied and the value of the upper critical magnetic field Hc3 at which superconductivity can nucleate is estimated. In addition, the authors locate the concentration of the order parameter, which depends on the inhomogeneous term a(x). Unlikely to the homogeneous case, the order parameter may concentrate in the interior of the superconducting material, due to the influence of the inhomogeneous term a(x).
基金support by the National Key Research and Development Program of China(2018YFA0704300)the National Natural Science Foundation of China(U1932217 and 11974246)+4 种基金the Natural Science Foundation of Shanghai(19ZR1477300)supported by MEXT Element Strategy Initiative to form Core Research Centerpartially supported by ChEM,SPST of ShanghaiTech University(02161943)Analytical Instrumentation Center(SPST-AIC10112914),SPST of ShanghaiTech Universitysupported by the National Natural Science Foundation of China(11888101)。
文摘Vacancies are prevalent and versatile in solid-state physics and materials science.The role of vacancies in strongly correlated materials,however,remains uncultivated until now.Here,we report the discovery of an unprecedented vacancy state forming an extended buckled-honeycomb-vacancy(BHV)ordering in Ir16Sb18.Superconductivity emerges by suppressing the BHV ordering through squeezing of extra Ir atoms into the vacancies or isovalent Rh substitution.The phase diagram on vacancy ordering reveals the superconductivity competes with the BHV ordering.Further theoretical calculations suggest that this ordering originates from a synergistic effect of the vacancy formation energy and Fermi surface nesting with a wave vector of(1/3,1/3,0).The buckled structure breaks the crystal inversion symmetry and can mostly suppress the density of states near the Fermi level.The peculiarities of BHV ordering highlight the importance of"correlated vacancies"and may serve as a paradigm for exploring other non-trivial excitations and quantum criticality.
