A New Numerical Method for Z(2) Topological Insulators with Strong Disorder

作者:Akagi Yutaka*; Katsura Hosho; Koma Tohru
来源:Journal of the Physical Society of Japan, 2017, 86(12): 123710.
DOI:10.7566/JPSJ.86.123710

摘要

We propose a new method to numerically compute the Z(2) indices for disordered topological insulators in Kitaev's periodic table. All of the Z(2) indices are derived from the index formulae which are expressed in terms of a pair of projections introduced by Avron, Seiler, and Simon. For a given pair of projections, the corresponding index is determined by the spectrum of the difference between the two projections. This difference exhibits remarkable and useful properties, as it is compact and has a supersymmetric structure in the spectrum. These properties enable highly efficient numerical calculation of the indices of disordered topological insulators. The method, which we propose, is demonstrated for the Bernevig-Hughes-Zhang and Wilson-Dirac models whose topological phases are characterized by a Z(2) index in two and three dimensions, respectively.

  • 出版日期2017-12-15