Interference effects in the light scattering spectra of semiconductors

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Abstract
We investigate the effect of plasmon-phonon coupling on the spectrum of laser light scattered by doped semiconductors under high-excitation conditions. A model consisting of the plasmon and LO-phonon subsystems in conditions of quasiequilibrium, characterized by uniform internal temperatures, is used. The scattering cross section is derived through an appropriate generalization of the fluctuation-dissipation theorem and the use of Bogoliubov's Green's-function formalizm. The Coulomb interaction between electrons is treated within the random-phase approximation and the Fröhlich Hamiltonian is used to describe the electron-phonon interaction. The phonon lifetime and plasma lifetime, other than Landau damping, are introduced in a phenomenological way. Numerical calculations for the case of a nondegenerate conduction-electron gas in GaAs are presented. The analysis is completed with a discussion of resonant Raman scattering when "hot" electrons are considered for the intermediate states of the scattering amplitude.