2ND-ORDER RESONANT RAMAN-SCATTERING IN SEMICONDUCTOR QUANTUM-WELLS UNDER HIGH MAGNETIC-FIELDS

We present a theoretical model of two-phonon resonant Raman scattering in a semiconductor quantum well (QW) in high magnetic fields. The Ram an profiles are studied as a function of magnetic field and laser freq uency in the backscattering configuration. Selection rules for Frohlic h electron-phonon interaction are given in the Faraday geometry assumi ng a three-band model which takes into account the heavy-light hole ad mixture in the valence band. It is shown that, due to mixing effects, Frohlich interaction contributes to the Raman spectra, not only in the parallel circular polarization configurations ((z) over bar(sigma(+/- ) , sigma(+/-))z), but also in the usually forbidden crossed polarizat ions ((z) over bar(sigma(+/-), sigma(+/-))z). Excitonic effects have b een taken into account. The corresponding Raman profiles are calculate d for a 35 ($) over cap GaAs/AlAs-QW taking into account the phonon co nfinement in the GaAs layer.