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

Optical phase coherence can be destroyed by various interaction mechan isms, including scattering by static disorder, electron-phonon interac tion and interaction among the optical excitations. The electron-phono n interaction strongly depends on the nature of the electronic states, which in turn is determined by the static disorder. It also gives ris e to hopping and phonon-induced delocalization, i.e. to transport. How ever, there is no one-to-one correspondence between transport processe s and dephasing processes in general. Only for strongly localized stat es can the dephasing rate be identified with the hopping rate. A gener al formulation of the problem is given and illustrated in terms of a s imple model system.