Resonant Rayleigh scattering by Wannierexcitons in a two-dimensional disordered potential

Abstract

Resonant Rayleigh scattering (RRS) in semiconductors is due toimperfections breaking the symmetry of translational invarianceof the crystal: impurities, defects or interfaces. The RRSobserved from semiconductor quantum wells (QWs) is mainly due tofluctuations in the lateral two-dimensional potential energyconfining charge carriers and excitons. Time resolving the RRSallows us to extract the statistical properties of the disorderpotential, including a certain degree of spatial correlation.Furthermore, the temporal coherence of RRS has been demonstratedby interferometric experiments with a single speckle, allowing usto discriminate RRS very clearly from incoherent fluorescence.This lively ongoing field of research has brought about genericfundamental notions readily applicable to spectroscopy of othersemiconductor nanostructures or possibly inorganic crystals,which are worth compiling. This paper aims at reviewing alarge fraction of the experiments carried out on GaAs QWs, which havecontributed significantly to the understanding of the static anddynamic properties of RRS.