Approximate symmetries and conservation laws in topological insulators and associated Z-invariants

Doll N, Schulz-Baldes H (2020)


Publication Type: Journal article

Publication year: 2020

Journal

Book Volume: 419

Article Number: 168238

DOI: 10.1016/j.aop.2020.168238

Abstract

Solid state systems with time reversal symmetry and/or particle–hole symmetry often only have Z2-valued strong invariants for which no general local formula is known. For physically relevant values of the parameters, there may exist approximate symmetries or almost conserved observables, such as the spin in a quantum spin Hall system with small Rashba coupling. It is shown in a general setting how this allows to define robust integer-valued strong invariants stemming from the complex theory, such as the spin Chern numbers, which modulo 2 are equal to the Z2-invariants. Moreover, these integer invariants can be computed using twisted versions of the spectral localizer.

Authors with CRIS profile

How to cite

APA:

Doll, N., & Schulz-Baldes, H. (2020). Approximate symmetries and conservation laws in topological insulators and associated Z-invariants. Annals of Physics, 419. https://dx.doi.org/10.1016/j.aop.2020.168238

MLA:

Doll, Nora, and Hermann Schulz-Baldes. "Approximate symmetries and conservation laws in topological insulators and associated Z-invariants." Annals of Physics 419 (2020).

BibTeX: Download