Floquet topological transitions in a driven one-dimensional topological insulator

TL;DR

This paper investigates how periodic driving influences the topological properties of a one-dimensional insulator, revealing the emergence and destruction of edge states through Floquet theory and Zak phase analysis.

Contribution

It introduces a detailed analysis of Floquet topological transitions in a driven SSH model, highlighting the interplay of photon-assisted processes and native topology.

Findings

Floquet driving creates new quasienergy gaps with edge states.

Original edge states can be destroyed or replaced by Floquet states.

The Zak phase analysis confirms the topological nature of Floquet bands.

Abstract

The Su-Schrieffer-Heeger model of polyacetylene is a paradigmatic Hamiltonian exhibiting non-trivial edge states. By using Floquet theory we study how the spectrum of this one-dimensional topological insulator is affected by a time-dependent potential. In particular, we evidence the competition among different photon-assisted processes and the native topology of the unperturbed Hamiltonian to settle the resulting topology at different driving frequencies. While some regions of the quasienergy spectrum develop new gaps hosting Floquet edge states, the native gap can be dramatically reduced and the original edge states may be destroyed or replaced by new Floquet edge states. Our study is complemented by an analysis of Zak phase applied to the Floquet bands. Besides serving as a simple example for understanding the physics of driven topological phases, our results could find a promising test-ground in cold matter experiments.