Skip to main content

Spin-orbit-free topological insulators

Author(s): Alexandradinata, A; Bernevig, Bogdan A.

To refer to this page use:
Abstract: We review a class of translational-invariant insulators without spin-orbit coupling, as may be realized in intrinsically spinless systems, e.g., photonic crystals and ultra-cold atoms. Some of these insulators have no time-reversal symmetry as well, i.e., the relevant symmetries are purely crystalline. Nevertheless, topological phases exist which are distinguished by their robust surface modes. To describe these phases, 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 Thouless-Kohmoto-Nightingale-Nijs invariant generalized to bent 2D manifolds. Like other well-known topological phases, their band topology is unveiled by the crystalline analog of Berry phases, i.e., parallel transport across certain non-contractible loops in the Brillouin zone. We also identify certain topological phases without any robust surface modes-they are uniquely distinguished by parallel transport along bent loops, whose shapes are determined by the symmetry group. Finally, we describe the Weyl semimetallic phase that intermediates two distinct, gapped phases.
Publication Date: Dec-2015
Electronic Publication Date: 25-Aug-2015
Citation: Alexandradinata, A, Bernevig, B Andrei. (2015). Spin-orbit-free topological insulators. PHYSICA SCRIPTA, T164 (10.1088/0031-8949/2015/T164/014013
DOI: doi:10.1088/0031-8949/2015/T164/014013
ISSN: 0031-8949
EISSN: 1402-4896
Type of Material: Journal Article
Journal/Proceeding Title: PHYSICA SCRIPTA
Version: Author's manuscript

Items in OAR@Princeton are protected by copyright, with all rights reserved, unless otherwise indicated.