Spinless Topological Insulators without Time-Reversal Symmetry
Strongly Correlated Electrons
2014-09-17 v1 Mesoscale and Nanoscale Physics
Abstract
We explore the 32 crystallographic point groups and identify topological phases of matter with robust surface modes. For n =3,4 and 6 of the C_{nv} groups, we find the first-known 3D topological insulators without spin-orbit coupling, and with surface modes that are protected only by point groups, i.e., not needing time-reversal symmetry. To describe these C_{nv} systems, we introduce the notions of (a) a halved mirror chirality: an integer invariant which characterizes half-mirror-planes in the 3D Brillouin zone, and (b) a bent Chern number: the traditional TKNN invariant generalized to bent 2D manifolds. We find that a Weyl semimetallic phase intermediates two gapped phases with distinct halved chiralities.
Cite
@article{arxiv.1402.6323,
title = {Spinless Topological Insulators without Time-Reversal Symmetry},
author = {A. Alexandradinata and Chen Fang and Matthew J. Gilbert and B. Andrei Bernevig},
journal= {arXiv preprint arXiv:1402.6323},
year = {2014}
}