Mapping the band structure of three-dimensional topological insulator Bi2Se3 in two-dimensional limit

ORAL

Abstract

In this work, with in situ angle-resolved photoemission spectroscopy, we have investigated the thickness dependent band structure of molecular beam epitaxy grown Bi2Se3, a typical three-dimensional insulator, from 1 quintuple layer (QL) up to 200QL. An energy gap is observed in the topologically protected metallic surface states of bulk Bi2Se3 below the thickness of 6QL, due to the coupling between the surface states from two opposite surfaces of the Bi2Se3 film. The gapped surface states exhibit sizable Rashba-type spin-orbit splitting, resulting from breaking of structural inversion symmetry induced by 6H-SiC substrate. The spin-splitting can be controlled by tuning the potential difference between the two surfaces, which can be utilized into electrical spin manipulation.

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Authors

  • Ke He

    • Institute of Physics, Chinese Academy of Sciences
    • Institute of Physics.CAS.China
    • Institute of Physics, The Chinese Academy of Sciences, Beijing 100190, P. R. China

  • Yi Zhang

    • Institute of Physics, Chinese Academy of Sciences

  • Cui-Zu Chang

    • Institute of Physics, Chinese Academy of Sciences

  • Can-Li Song

    • Institute of Physics, Chinese Academy of Sciences
    • Institute of Physics.CAS.China

  • Lili Wang

    • Institute of Physics, Chinese Academy of Sciences
    • Institute of Physics.CAS.China
    • Institute of Physics, The Chinese Academy of Sciences, Beijing 100190, P. R. China

  • Xucun Ma

    • Institute of Physics, Chinese Academy of Sciences
    • Institute of Physics.CAS.China
    • Institute of Physics, The Chinese Academy of Sciences, Beijing 100190, P. R. China

  • Zhong Fang

    • The Institute of Physics, Chinese Academy of Sciences P.O. Box 603, Beijing 100190, China
    • Institute of Physics, Chinese Academy of Sciences
    • Institute of Physics, The Chinese Academy of Sciences, Beijing 100190, P. R. China

  • Xi Dai

    • The Institute of Physics, Chinese Academy of Sciences P.O. Box 603, Beijing 100190, China
    • Institute of Physics, Chinese Academy of Sciences

  • Wen-Yu Shan

    • The University of Hong Kong

  • Shun-Qing Shen

    • The University of Hong Kong

  • Qian Niu

    • University of Texas at Austin
    • Department of Physics, The University of Texas, Austin, Texas 78712, USA
    • The University of Texas, Austin

  • Xiao-Liang Qi

    • Stanford University
    • Dept. Physics, Stanford Univ
    • Microsoft Station Q
    • Department of Physics, Stanford University

  • Shoucheng Zhang

    • Stanford University
    • Dept. Physics, Stanford Univ
    • Department of Physics, Stanford University

  • Xi Chen

    • Tsinghua University
    • Tsinghua University.China

  • Jin-Feng Jia

    • Tsinghua University
    • Tsinghua University.China

  • Qi-Kun Xue

    • Tsinghua University
    • Tsinghua University.China
    • Key Lab for Atomic, Molecular and Nanoscience, Department of Physics, Tsinghua University, Beijing 100084, P. R. China