Floquet topological phases on a honeycomb lattice using elliptically polarized light

TL;DR

This paper investigates how elliptically polarized light can induce and control topological phases in a honeycomb lattice, revealing a method to switch between trivial and topological states via external drive parameters.

Contribution

It introduces a comprehensive analysis of Floquet topological phases driven by elliptically polarized light on a honeycomb lattice, highlighting control over topological transitions through drive amplitude ratios.

Findings

Varying the drive ratio induces topological phase transitions.

Floquet Chern number characterizes the topological phases.

Edge modes are robust in topological phases.

Abstract

We study the effect of driving a two-dimensional honeycomb system out of equilibrium using an elliptically polarized light as a time-dependent perturbation. In particular, we try to understand the topological phase diagram of this driven system when the external drive is a vector potential given by ${\bf A}(t) = (A_{0x} \cos(\Omega t), A_{0y} \cos(\Omega t + \phi_0))$. These topological phases are characterized by the Floquet Chern number which, in each of these phases, is related to the number of robust edge modes on a nanoribbon. We show that varying the ratio $A_{0x}/A_{0y}$ of the external drive is a possible way to take the system from a trivial to a topological phase and vice versa.