PT Symmetric Floquet Topological Phase in SSH Model

TL;DR

This paper explores a periodically modulated SSH model with gain and loss, revealing stable Floquet topological phases in a non-Hermitian, PT symmetric system under certain conditions, with potential photonic applications.

Contribution

It introduces a Floquet topological phase in a PT symmetric, non-Hermitian SSH model, analyzing conditions for stability and topological properties using Floquet theory.

Findings

Stable Floquet topological phase exists at high oscillation frequencies.

Critical non-Hermitian degree limits the topological phase stability.

Quasi-energy spectrum reveals topological characteristics.

Abstract

We consider periodically modulated Su-Schrieffer-Heeger (SSH) model with gain and loss. This model, which can be realized with current technology in photonics using waveguides, allows us to study Floquet topological insulating phase. By using Floquet theory, we find the quasi-energy spectrum of this one dimensional PT symmetric topological insulator. We show that stable Floquet topological phase exists in our model provided that oscillation frequency is large and the non-Hermitian degree is below than a critical value.