Topological Anderson insulators induced by random binary disorders

TL;DR

This paper demonstrates that random binary disorders can induce topological Anderson insulating phases in a one-dimensional Su-Schrieffer-Heeger model, extending the understanding of disorder-induced topological phenomena.

Contribution

It reveals how correlated binary disorders can generate topological phases, supported by analytical and numerical methods, in a model previously studied mainly with uncorrelated disorder.

Findings

Binary disorders induce topological Anderson insulators in the SSH model.

Topological phases characterized by winding number and localization measures.

Phase boundaries match analytical self-consistent Born results.

Abstract

Different disorders lead to various localization and topological phenomena in condensed matter and artificial systems. Here we study the topological and localization properties in one-dimensional Su-Schrieffer-Heeger model with spatially correlated random binary disorders. It is found that random binary disorders can induce the topological Anderson insulating phase from the trivial insulator in various parameter regions. The topological Anderson insulators are characterized by the disorder-averaged winding number and localized bulk states revealed by the inverse participation ratio in both real and momentum spaces. We show that the topological phase boundaries are consistent with the analytical results of the self-consistent Born approach and the localization length of zero-energy modes, and discuss how the bimodal probability affects the disorder-induced topological phases. The topological characters can be detected from the mean chiral displacement in atomic or photonic systems. Our work provides an extension of the topological Anderson insulators to the case of correlated disorders.