INTERACTION-INDUCED ELECTRON SELF-INTERFERENCE IN A SEMICONDUCTOR - THE PHONON STAIRCASE EFFECT

The exact quantum mechanics of a model semiconductor system of an elec tron with a discrete and equidistant energy spectrum interacting with a single phonon mode is presented. An electron initially excited into a coherent superposition of states interacts with phonons thereby crea ting a self-interference in time which reduces the emission of phonons to isolated bursts. This self-interference effect gives rise to stepl ike behavior in the relaxation kinetics of the electron and phonons. W e show that this ''phonon staircase'' effect is a consequence of a cor related initial electron distribution and the violation of energy cons ervation in the electron-phonon interaction on short time scales.