Predictive microscopic approach to transport in THz quantum cascade lasers

In this paper we present further details of a predictive Keldysh nonequilibrium many body Green's functions theory for quantum transport including high order electron-electron, electron-phonon, electron-impurity and interface roughness scattering processes. Our approach is fully frequency and momentum dependent. Local current conservation is observed even if only few states are considered. The resulting algorithm has led to good agreement with experimental observations.