摘要
Vortices and bound states offer an effective means of comprehending the electronic properties of superconductors.Recently,surface-dependent vortex core states have been observed in the newly discovered kagome superconductors CsV_(3)Sb_(5).Although the spatial distribution of the sharp zero energy conductance peak appears similar to Majorana bound states arising from the superconducting Dirac surface states,its origin remains elusive.In this study,we present observations of tunable vortex bound states(VBSs)in two chemically-doped kagome superconductors Cs(V_(1-x)Tr_(x))_(3)Sb_(5)(Tr=Ta or Ti),using low-temperature scanning tunneling microscopy/spectroscopy.The CsV_(3)Sb_(5)-derived kagome superconductors exhibit full-gap-pairing superconductivity accompanied by the absence of long-range charge orders,in contrast to pristine CsV_(3)Sb_(5).Zero-energy conductance maps demonstrate a field-driven continuous reorientation transition of the vortex lattice,suggesting multiband superconductivity.The Ta-doped CsV_(3)Sb_(5)displays the conventional cross-shaped spatial evolution of Caroli-de Gennes-Matricon bound states,while the Tidoped CsV_(3)Sb_(5)exhibits a sharp,non-split zero-bias conductance peak(ZBCP)that persists over a long distance across the vortex.The spatial evolution of the non-split ZBCP is robust against surface effects and external magnetic field but is related to the doping concentrations.Our study reveals the tunable VBSs in multiband chemically-doped CsV_(3)Sb_(5)system and offers fresh insights into previously reported Y-shaped ZBCP in a non-quantum-limit condition at the surface of kagome superconductor.
作者
黄子豪
韩相和
赵振
刘锦锦
李鹏飞
谭恒心
王秩伟
姚裕贵
杨海涛
颜丙海
蒋坤
胡江平
汪自强
陈辉
高鸿钧
Zihao Huang;Xianghe Han;Zhen Zhao;Jinjin Liu;Pengfei Li;Hengxin Tan;Zhiwei Wang;Yugui Yao;Haitao Yang;Binghai Yan;Kun Jiang;Jiangping Hu;Ziqiang Wang;Hui Chen;Hong-Jun Gao(Beijing National Center for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100190,China;Centre for Quantum Physics,Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE),School of Physics,Beijing Institute of Technology,Beijing 100081,China;Beijing Key Lab of Nanophotonics and Ultrafine Optoelectronic Systems,Beijing Institute of Technology,Beijing 100081,China;Department of Condensed Matter Physics,Weizmann Institute of Science,Rehovot 7610001,Israel;Hefei National Laboratory,Hefei 230088,China;Department of Physics,Boston College,Chestnut Hill MA 02467,USA)
基金
supported by the National Natural Science Foundation of China(61888102,52022105,92065109,and 12174428)
the National Key Research and Development Projects of China(2022YFA1204100,2018YFA0305800,2019YFA0308500,2020YFA0308800,and 2022YFA1403400)
the CAS Project for Young Scientists in Basic Research(YSBR-003 and 2022YSBR-048)
the Innovation Program of Quantum Science and Technology(2021ZD0302700)
the financial support from the European Research Council(ERC Consolidator Grant “Nonlinear Topo”,No.815869)
ISF-Singapore-Israel Research Grant(3520/20)
supported by the US DOE,Basic Energy Sciences(DE-FG02-99ER45747)。
