A dynamic Green's function theory for a highly excited direct gap semiconductor

The problem of highly excited semiconductors is treated self-consistently with respect to carrier as well as photon dynamics by a new Green's function (GF) technique. With the help of this method the shortcoming of quasi-static considerations has been overcome by a new concept of separation of fast and slowly moving observables. The inhomogeneities of the GF equations of motion are solutions of kinetic equations in the slow time scale. In this concept the total spectral weight function for conduction band electrons is obtained in a femtosecond time scale of the laser pulse duration.