The structure and edge states of two-dimensional few-layer Bi(110)films grown on a graphene/SiC substrate were studied by low-temperature scanning tunneling microscopy and spectroscopy.We found that the local density ...The structure and edge states of two-dimensional few-layer Bi(110)films grown on a graphene/SiC substrate were studied by low-temperature scanning tunneling microscopy and spectroscopy.We found that the local density of states of few-layer Bi(110)films are layer-dependent and that the films transition from exhibiting semiconducting characteristics to metallic ones as the number of layers increases.The in-plane lattice structure has numerous displacements and inversions,which implies that the atomic arrangement and atomic buckling in ultrathin Bi(110)films are flexible.The edges formed between 4-monolayer Bi(110)and graphene are reconstructed and distorted,and the corresponding edge states are topographically dependent.Steps from the substrate and domain boundaries also modify the electronic structures and induce additional defect-dependent states.We also found that the zigzag-shaped step edges in few-layer Bi(110)films are nonreconstructed and possess layer-dependent homogeneous edge states,providing a very likely platform for further research on quantum interference of the edge mode in order to confirm the topology in Bi(110).展开更多
基金U.S.Air Force Office of Scientific Research Grants FA9550-15-1-0236 and FA9550-20-1-0068,the T.L.L.Temple Foundation,the John J.and Rebecca Moores Endowment,and the State of Texas through the Texas Center for Superconductivity at the University of Houston.
文摘The structure and edge states of two-dimensional few-layer Bi(110)films grown on a graphene/SiC substrate were studied by low-temperature scanning tunneling microscopy and spectroscopy.We found that the local density of states of few-layer Bi(110)films are layer-dependent and that the films transition from exhibiting semiconducting characteristics to metallic ones as the number of layers increases.The in-plane lattice structure has numerous displacements and inversions,which implies that the atomic arrangement and atomic buckling in ultrathin Bi(110)films are flexible.The edges formed between 4-monolayer Bi(110)and graphene are reconstructed and distorted,and the corresponding edge states are topographically dependent.Steps from the substrate and domain boundaries also modify the electronic structures and induce additional defect-dependent states.We also found that the zigzag-shaped step edges in few-layer Bi(110)films are nonreconstructed and possess layer-dependent homogeneous edge states,providing a very likely platform for further research on quantum interference of the edge mode in order to confirm the topology in Bi(110).
