Light Induced Topological Phenomena

We show that topological states can be induced in two and three dimensional semiconductors initially in the trivial phase by irradiation with microwave frequencies without changing well structure or material properties closing the gap and crossing the phase transition The topological phenomena is analyzed in terms of Floquet theory for periodically driven system We discuss different classes of topological phenomena in such systems and show that their quasi energy spectrum can exhibit robust edge or surface states Intriguingly we show that periodically driven systems can e