First-order resonant Raman scattering under an electric field.

Abstract

We derive theoretical expressions for the efficiency of one-LO-phonon Raman scattering under the presence of an electric field. Both Fr\"ohlich and deformation potential electron-phonon interactions are considered. The calculated LO-phonon Raman intensity shows oscillations vs electric field for excitation energies above the fundamental gap ${\mathit{E}}_{0}$. These results explain recently reported experimental data on electric-field-induced Raman scattering in GaAs obtained at room temperature, as well as additional data presented here which were taken at 10 K. The theoretical model allows us to assign different origins to the electro-Raman oscillations depending on the mediating electron-phonon interaction: (a) interference between the scattering amplitude for heavy-hole and split-off intraband processes in the case of Fr\"ohlich interaction, (b) scattering amplitude involving the light-hole--heavy-hole interband transitions in the case of deformation potential interaction. For parallel polarizations along [110] or [11\ifmmode\bar\else\textasciimacron\fi{}0] interference effects between the (a) and (b) scattering amplitudes are observed. \textcopyright{} 1996 The American Physical Society.