Floquet topological phases on a honeycomb lattice using elliptically polarized light

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.