A comparison between resonant Raman scattering in type II GaAs/AlAs superlattices and single GaAs quantum wells

We present a comparison between resonant Raman scattering experiments on a type II GaAs/AlAs superlattice of short period and a single GaAs quantum well. Under resonant excitation, a continuous emission is observed in the low-frequency range of the two heterostructure Raman spectra. This scattering is analyzed in terms of breakdown of the wavevector conservation law due to single quantum-well effects. In the optical regions, strong similarities are also observed. Doubly resonant Raman scattering processes of symmetric and antisymmetric interface modes are specified and discussed within disorder effects. Finally, lateral extents of in-plane microroughnesses detected by acoustic and interface phonons, are estimated.