Topological phase in a non-Hermitian PT symmetric system

TL;DR

This paper demonstrates the existence of topologically nontrivial edge states with real spectra in a non-Hermitian PT symmetric system modeled by a generalized Aubry-Andre lattice with impurities.

Contribution

It introduces a non-Hermitian extension of the Aubry-Andre model showing topological edge states in PT symmetric conditions for the first time.

Findings

Existence of topologically nontrivial edge states with real spectra

Edge states appear in the PT symmetric phase

Non-Hermitian impurities induce topological phenomena

Abstract

In this work, we consider a tight binding lattice with two non-Hermitian impurities. The system is described by a non-Hermitian generalization of the Aubry Andre model. We show for the first time that there exists topologically nontrivial edge states with real spectra in the PT symmetric region.