Doubly resonant LO-phonon Raman scattering via the deformation potential with a single quantum well

Doubly resonant Raman scattering (DRRS) due to LO phonons where the incoming and outgoing photons are resonant with the $n=1\mathrm{}$ light- and heavy-hole free excitons, respectively, has been observed at low temperature with a very-high-quality single GaAs quantum well of estimated thickness 28.3 Å. The measured circular and linear polarization characteristics of this DRRS show that it is dominated by the deformation-potential process modified by considerable spin relaxation and an admixture of about 8% Fröhlich scattering. In contrast to bulk GaAs, interference between these two processes is not observed or expected for DRRS.