摘要
Topologically nontrivial Fe-based superconductors attract extensive attentions due to their ability of hosting Majorana zero modes(MZMs)which could be used for topological quantum computation.Topological defects such as vortex lines are required to generate MZMs.Here,we observe the robust edge states along the surface steps of CaKFe_(4)As_(4).Remarkably,the tunneling spectra show a sharp zero-bias peak(ZBP)with multiple integerquantized states at the step edge under zero magnetic field.We propose that the increasing hole doping around step edges may drive the local superconductivity into a state with possible spontaneous time-reversal symmetry breaking.Consequently,the ZBP can be interpreted as an MZM in an effective vortex in the superconducting topological surface state by proximity to the center of a tri-junction with different superconducting order parameters.Our results provide new insights into the interplay between topology and unconventional superconductivity,and pave a new path to generate MZMs without magnetic field.
作者
Lu Cao
Geng Li
Wenyao Liu
Ya-Bin Liu
Hui Chen
Yuqing Xing
Lingyuan Kong
Fazhi Yang
Quanxin Hu
Meng Li
Xingtai Zhou
Zichao Chen
Chenhang Ke
Lunhui Hu
Guang-Han Cao
Congjun Wu
Hong Ding
Hong-Jun Gao
曹路;李更;刘文尧;刘亚彬;陈辉;邢宇庆;孔令元;杨发枝;胡全欣;李萌;周兴泰;陈子超;柯晨航;胡仑辉;曹光旱;吴从军;丁洪;高鸿钧(Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Hefei National Laboratory,Hefei 230088,China;Department of Physics,Zhejiang University,Hangzhou 310027,China;New Cornerstone Science Laboratory,Department of Physics,School of Science,Westlake University,Hangzhou 310024,China;Institute for Theoretical Sciences,Westlake University,Hangzhou 310024,China;Key Laboratory for Quantum Materials of Zhejiang Province,School of Science,Westlake University,Hangzhou 310024,China;Institute of Natural Sciences,Westlake Institute for Advanced Study,Hangzhou 310024,China;Tsung-Dao Lee Institute,and New Cornerstone Science Laboratory,Shanghai Jiao Tong University,Shanghai 201210,China)
基金
supported by the National Key Research and Development Program of China(Grant No.2019YFA0308500)
the National Natural Science Foundation of China(Grant Nos.62488201,52072401,11888101,12234016,and 12174317)
the Chinese Academy of Sciences(Grant No.YSBR-003)
the Innovation Program of Quantum Science and Technology(Grant No.2021ZD0302700)
the New Cornerstone Science Foundation
the China Postdoctoral Science Foundation(Grant No.2022M723111)
the Fellowship of China National Postdoctoral Program for Innovative Talents(Grant No.BX20230358)。
