Relaxation properties of the quantum kinetics of carrier-LO-phonon interaction in quantum wells

Abstract

We compare numerically the carrier-LO-phonon quantum kinetics as provided by the twotime Green's function formalism on the one hand and its one-time approximation given by the generalized Kadanoff-Baym ansatz on the other hand. Self-consistent RPA self-energies are used in both cases. The aim of the analysis is to check the correct thermalization behaviour of the solutions. It is shown that both formalisms give rise to steady states in the long time limit. It is shown that these states correspond to the correct thermal equilibrium for the two-time solutions, while the one-time approach fails to thermalize the carriers in the interemediate-coupling regime. The thermalization criterion used is the KMS condition. © 2006 IOP Publishing Ltd.