Resonant rayleigh scattering in ordered and disordered semiconductor superlattices

We report the experimental study of resonant Rayleigh scattering in GaAs-AlGaAs superlattices with ordered and intentionally disordered potential profiles (correlated and uncorrelated) in the growth direction z. We show that the intentional disorder along z modifies markedly the energy dispersion of the dephasing rates of the excitons. The application of an external magnetic field in the same direction allows us to modify the exciton localization and to study the relative modification of the exciton dephasing, energies, and linewidth.