Frequency-Dependent Relaxation Time of Electron-Phonon Systems

Abstract

A derivation of the frequency-dependent relaxation time in a simple model of metal, composed of electrons and phonons, is presented. The problem is investigated by a quantum-kinetic description of the response of the electron-phonon system to an oscillating electric field. The treatment, which stems from a proper time-dependent transport equation, does not have the time scale restriction of the usual transition probability approach, and does give a proper description of the time-dependent collective effects.