Resonant Raman study of low temperature exciton localization in GaAs quantum wells.

We have observed an unexpected temperature dependence in the intensity of Raman scattering resonant with the ground state exciton in GaAs-AlGaAs quantum well heterostructures. We show that the temperature dependence is related to the homogeneous linewidth for quantum well excitons and yields new insight into low temperature exciton localization.