PT symmetry protected non-Hermitian topological systems

C Yuce,Z Oztas

doi:10.1038/s41598-018-35795-5

Abstract

We study PT symmetry protected topological phase in non-Hermitian 1D and 2D systems. We show that topological phase exist in non-Hermitian PT symmetric systems for both gapped and gapless systems and discuss appearance of exceptional points. We apply our formalism to a complex extension of the SSH model, topological semimetals and nodal superconductors.

Highlights

Topological phase in non-Hermitian systems is an emergent field of study that has applications in topological photonics[1]
To study symmetry-protected topological phase in non-Hermitian systems, we begin with definitions of four basic types of symmetries for translational invariant systems
Can we find topological edge states with real valued energy eigenvalues at the interface of these two topologically distinct systems with real spectra? As opposed to Hermitian systems, our non-Hermitian system breaks PT symmetry during topological phase transition

Summary

Introduction

Topological phase in non-Hermitian systems is an emergent field of study that has applications in topological photonics[1]. We study parity-time symmetric non-Hermitian topological phase. To study PT symmetry protected topological phase in non-Hermitian systems, we consider the following topologically insulating two band model Exceptional points occurs and the system enters into region where complex energy eigenvalues appear.

Results

Conclusion