Local formula for the $Z_2$ invariant of topological insulators
Mesoscale and Nanoscale Physics
2019-11-07 v3 Mathematical Physics
math.MP
Abstract
We proposed a formula for the invariant for topological insulators, which remains valid without translational invariance. Our formula is a local expression, in the sense that the contributions mainly come from quantities near a point. Using almost commute matrices, we proposed a method to approximate this invariant with local information. The validity of the formula and the approximation method is proved.
Keywords
Cite
@article{arxiv.1905.12649,
title = {Local formula for the $Z_2$ invariant of topological insulators},
author = {Zhi Li and Roger S. K. Mong},
journal= {arXiv preprint arXiv:1905.12649},
year = {2019}
}
Comments
Final version published on PRB