2-PHONON MAGNETO-RAMAN SCATTERING IN QUANTUM-WELLS - FROHLICH INTERACTION

We have developed a theoretical model of two-phonon resonant magneto-R aman scattering in a semiconductor quantum well (QW). Frohlich electro n-phonon interaction has been considered and the corresponding selecti on rules are derived for Faraday geometry and backscattering configura tion. The resonant profiles are analyzed as a function of magnetic fie ld and laser energy. To simplify the discussion a three-band model wit h parabolic masses has been used as a first approach, studying later t he role of heavy-hole light-hole admixture in the scattering process. It is shown that, due to mixing effects, Frohlich interaction contribu tes to the two-phonon Raman spectra in the parallel ((z) over bar(sigm a(+/-), sigma(+/-)) z) and also in the usually forbidden crossed ((z) over bar(sigma(+/-), sigma(+/-)) z) polarizations. The model has been used to calculate the two-phonon magneto-Raman spectra of a 35 Angstro m GaAs/AlAs QW as an example.