Stable topological edge states in a non-Hermitian four-band model

TL;DR

This paper presents a non-Hermitian four-band model exhibiting stable topological edge states protected by symmetries, with potential applications in topological lasers.

Contribution

It introduces a new non-Hermitian four-band lattice model with stable topological edge states and discusses its use as a topological laser.

Findings

Stable topological edge states protected by symmetries

Topological phase emergence in the system

Potential for topological laser applications

Abstract

We introduce a one dimensional non-Hermitian four band tight binding lattice system. We find stable topological edge states protected by particle-hole and parity-time symmetries. We show that topological phase appears in the system. We discuss that the system can also be used as a topological laser if the gain and loss positions in a unit cell are judiciously arranged.