Topological surface states and flat bands in the kagome superconductor CsV_(3)Sb_(5)  

笼目超导体CsV_(3)Sb_(5)中的拓扑表面态和平带的光电子谱证据

作　　者：Yong Hu Samuel M.L.Teicher Brenden R.Ortiz Yang Luo Shuting Peng Linwei Huai Junzhang Ma Nicholas CPlumb Stephen D.Wilson Junfeng He Ming Shi 胡勇;Samuel M.L.Teicher;Brenden R.Ortiz;罗洋;彭舒婷;淮琳崴;马均章;Nicholas CPlumb;Stephen D.Wilson;何俊峰;史明(Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics,University of Science and Technology of China,Hefei 230026,China;Swiss Light Source,Paul Scherrer Institute,Villigen PSI CH-5232,Switzerland;Materials Department and California Nanosystems Institute,University of California Santa Barbara,Santa Barbara,CA93106,USA;Department of Physics,City University of Hong Kong,Hong Kong,China)

机构地区：[1]Department of Physics and CAS Key Laboratory of Strongly-coupled Quantum Matter Physics,University of Science and Technology of China,Hefei 230026,China [2]Swiss Light Source,Paul Scherrer Institute,Villigen PSI CH-5232,Switzerland [3]Materials Department and California Nanosystems Institute,University of California Santa Barbara,Santa Barbara,CA93106,USA [4]Department of Physics,City University of Hong Kong,Hong Kong,China

出　　处：《Science Bulletin》2022年第5期495-500,M0004,共7页科学通报（英文版）

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);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-1906325;the 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-1720256;support from the California NanoSystems Institute through the Elings Fellowship program;supported by the National Science Foundation Graduate Research Fellowship Program(DGE-1650114)。

摘　　要：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.具有多种电子序和丰富物态的量子材料中往往蕴含着奇异的量子现象.不同电子序和量子态之间的相互作用也可以产生新的物理现象.本文揭示了笼目超导体CsV_(3)Sb_(5)的独特电子结构.作者在费米能附近发现了拓扑非平庸的表面态,这意味着拓扑物理很可能会参与到超导态中;同时还直接观测到了平带,这表明电子关联作用会在笼目超导体CsV_(3)Sb_(5)中起着重要的作用.这些结果表明笼目晶格CsV_(3)Sb_(5)不仅具有实现马约拉纳零模和奇异超导态的潜力,还是一个独特的可用于探索电荷密度波有序、拓扑量子态、强关联效应和超导性之间的相互作用的研究平台.

关 键 词：ARPES Kagome superconductors Charge density wave order Topologically nontrivial surface states 

分 类 号：O469[理学—凝聚态物理]