Anomalous helical edge states in a non-Hermitian Chern insulator

TL;DR

This paper explores a non-Hermitian Chern insulator revealing unique anomalous helical edge states localized at one edge, expanding understanding of topological phases in non-Hermitian systems.

Contribution

It introduces the concept of anomalous helical edge states in non-Hermitian Chern insulators, showing their existence alongside traditional chiral edge states.

Findings

Anomalous helical edge states are localized at only one edge.

These states are unique to non-Hermitian topological systems.

The bulk-boundary correspondence is extended to include these new edge states.

Abstract

A non-Hermitian extension of a Chern insulator and its bulk-boundary correspondence are investigated. It is shown that in addition to the robust chiral edge states that reflect the nontrivial topology of the bulk (nonzero Chern number), anomalous helical edge states localized only at one edge can appear, which are unique to the non-Hermitian Chern insulator.