Electron-phonon interaction and coupled phonon-plasmon modes

The theory of Raman scattering by the coupled electron-phonon system in metals and heavily doped semiconductors is developed with Coulomb screening and the electron-phonon deformation interaction taken into account. The Boltzmann equation for carriers is applied. Phonon frequencies and optic coupling constants are renormalized due to interactions with carriers. The k-dependent semiclassical dielectric function is employed instead of the Lindhard-Mermin expression. The results of calculations are presented for various values of the carrier concentration and the electron-phonon coupling constant.