• 文献标题:   Two-Dimensional Topological Insulator State and Topological Phase Transition in Bilayer Graphene
  • 文献类型:   Article
  • 作  者:   QIAO ZH, TSE WK, JIANG H, YAO YG, NIU Q
  • 作者关键词:  
  • 出版物名称:   PHYSICAL REVIEW LETTERS
  • ISSN:   0031-9007 EI 1079-7114
  • 通讯作者地址:   Univ Texas Austin
  • 被引频次:   108
  • DOI:   10.1103/PhysRevLett.107.256801
  • 出版年:   2011

▎ 摘  要

We show that gated bilayer graphene hosts a strong topological insulator (TI) phase in the presence of Rashba spin-orbit (SO) coupling. We find that gated bilayer graphene under preserved time-reversal symmetry is a quantum valley Hall insulator for small Rashba SO coupling lambda(R), and transitions to a strong TI when lambda(R) > root U-2 + t(perpendicular to)(2), where U and t(perpendicular to) are, respectively, the interlayer potential and tunneling energy. Different from a conventional quantum spin Hall state, the edge modes of our strong TI phase exhibit both spin and valley filtering, and thus share the properties of both quantum spin Hall and quantum valley Hall insulators. The strong TI phase remains robust in the presence of weak graphene intrinsic SO coupling.