Skip to main content

Spin-Orbit-Free Topological Insulators without Time-Reversal Symmetry

Author(s): Alexandradinata, A; Fang, Chen; Gilbert, Matthew J; Bernevig, Bogdan A.

To refer to this page use:
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., the relevant symmetries are purely crystalline and do not include time reversal. 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 Thouless-Kohmoto-Nightingale-den Nijs invariant generalized to bent 2D manifolds. We find that a Weyl semimetallic phase intermediates two gapped phases with distinct halved chiralities. In addition to electronic systems without spin-orbit coupling, our findings also apply to intrinsically spinless systems such as photonic crystals and ultracold atoms.
Publication Date: 12-Sep-2014
Electronic Publication Date: 12-Sep-2014
Citation: Alexandradinata, A, Fang, Chen, Gilbert, Matthew J, Bernevig, B Andrei. (2014). Spin-Orbit-Free Topological Insulators without Time-Reversal Symmetry. PHYSICAL REVIEW LETTERS, 113 (10.1103/PhysRevLett.113.116403
DOI: doi:10.1103/PhysRevLett.113.116403
ISSN: 0031-9007
EISSN: 1079-7114
Type of Material: Journal Article
Journal/Proceeding Title: PHYSICAL REVIEW LETTERS
Version: Final published version. Article is made available in OAR by the publisher's permission or policy.

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