Photo-Induced Floquet Effects in Semiconductor Excitons

Recently, Floquet band engineering has emerged as a new approach to manipulate the properties of solid state systems. A prominent example of such investigations is creating non-trivial topological effects using Floquet physics. However, usually in such studies the presence of Coulomb interaction that can lead to important interacting phenomena such as the presence of bound states is ignored. In this work, we consider a driven semiconductor in the presence of strong Coulomb interactions with a weak coupling to a thermal reservoir. Using a rotating wave approximation to Bethe-Salpeter equations, we study the formation of excitonic quasiparticles in this system and in particular, we calculate the excitons' spectrum as a function of the frequency and amplitude of the drive. We compare our results with conventional non-driven excitons and we propose experimental features to detect the new physics found here.