A semi-classical Floquet-NEGF approach to model photon-assisted tunneling in quantum well devices

The non-equilibrium Green’s function formalism is often employed to model photon-assisted tunneling processes in opto-electronic quantum well devices. For this purpose, self-consistent schemes based on a quantum electrodynamical description of light–matter interactions have been proposed before. However, these schemes are typically computationally very demanding. Therefore, in this work, a novel semi-classical method based on Floquet–Green theory is proposed, which strongly mitigates the computational costs. By comparison to results obtained with a traditional, purely quantum mechanical technique, the new approach is validated, shown to be faster, and exhibits superior convergence properties. Finally, a two-band model for superlattice structures is constructed to further illustrate the advantages of the novel, advocated method.