The Electron—Phonon Interaction

Abstract

As we have seen in Chap. 10, the Green’s function theory offers a systematic way to describe many-particle systems under arbitrary nonequilibrium conditions. Up to now, however, we have restricted ourselves to a rigid lattice. Under these conditions, nonequilibrium concerns only the particle system. The time evolution into a true quasi-equilibrium state, however, requires dis-sipative processes, i.e. the transfer of energy from the particle system to the lattice, which results from interaction with lattice vibrations. Moreover, completely different nonequilibrium states can arise because of this interaction, in particular if the lattice itself is driven out of equilibrium by interaction with the particle system. Thus our theory of scattering processes developed so far needs improvement.