New Journal of Physics (Jan 2018)

Connection topology of step edge state bands at the surface of a three dimensional topological insulator

  • Yishuai Xu,
  • Guodong Jiang,
  • Janet Chiu,
  • Lin Miao,
  • Erica Kotta,
  • Yutan Zhang,
  • Rudro R Biswas,
  • L Andrew Wray

DOI
https://doi.org/10.1088/1367-2630/aacef6
Journal volume & issue
Vol. 20, no. 7
p. 073014

Abstract

Read online

Topological insulators (TIs) in the Bi _2 Se _3 family manifest helical Dirac surface states that span the topologically ordered bulk band gap. Recent scanning tunneling microscopy measurements have discovered additional states in the bulk band gap of Bi _2 Se _3 and Bi _2 Te _3 , localized at one-dimensional step edges. Here numerical simulations of a TI surface are used to explore the phenomenology of edge state formation at the single-quintuple layer step defects found ubiquitously on these materials. The modeled one-dimensional edge states are found to exhibit a stable topological connection to the two-dimensional surface state Dirac point.

Keywords