FIRST-ORDER RESONANT RAMAN-SCATTERING UNDER AN ELECTRIC-FIELD

We derive theoretical expressions for the efficiency of one-LO-phonon Raman scattering under the presence of an electric field. Both Frohlic h and deformation potential electron-phonon interactions are considere d. The calculated LO-phonon Raman intensity shows oscillations vs elec tric field for excitation energies above the fundamental gap E(0). The se results explain recently reported experimental data on electric-fie ld-induced Raman scattering in GaAs obtained at room temperature, as w ell as additional data presented here which were taken at 10 K. The th eoretical model allows us to assign different origins to the electro-R aman oscillations depending on the mediating electron-phonon interacti on: (a) interference between the scattering amplitude for heavy-hole a nd split-off intraband processes in the case of Frohlich interaction, (b) scattering amplitude involving the light-hole-heavy-hole interband transitions in the case of deformation potential interaction. For par allel polarizations along [110] or <[1(1)over bar0]> interference effe cts between the (a) and (b) scattering amplitudes are observed.