OPTICAL-PHASE RELAXATION IN DISORDERED SEMICONDUCTORS DUE TO ELECTRON-PHONON COUPLING

Optical phase coherence can be destroyed by various interaction mechanisms, including scattering by static disorder, electron-phonon interaction and interaction among the optical excitations. The electron-phonon interaction strongly depends on the nature of the electronic states, which in turn is determined by the static disorder. It also gives rise to hopping and phonon-induced delocalization, i.e. to transport. However, there is no one-to-one correspondence between transport processes and dephasing processes in general. Only for strongly localized states can the dephasing rate be identified with the hopping rate. A general formulation of the problem is given and illustrated in terms of a simple model system.