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.
Categories: cond-mat.mes-hall cond-mat.mtrl-sci