Kinetic equations in an electron-phonon system

A method for deriving the kinetic equations describing the interactions of electrons with phohens is described. The result was obtained without solving the equations for the simultaneous correlation functions. The classical electron–phonon collision integral has a Fokker–Planck form, while the quantum integral differs from the known Bloch theory expression by the consideration of polarization. Consideration of polarization leads to sound velocity change andto the interaction of electrons by means of the exchange of virtual phonons. Using the collision integrals obtained, the relaxation of the directionaI velocity and energy of electrons resulting from electron-phonon collisions was considered. A model integral for electron-phonon collisions, which correctly described such relaxation processes, was constructed.