Exciton-exciton interaction through barrier layer

We demonstrate that the radiative recombination of an exciton in a GaAs/AlGaAs quantum well (QW) is slowed down by the exciton-exciton scattering caused by the high-density excitons, which are injected into the exciton reservoir in the vicinity of the QW by an ultra-fast laser. Our experiment shows lifetime prolongation (up to 30% at a density of 1 x 10(17)/cm(3) in the reservoir) and lifetime saturation of exciton in QW. The lifetime prolongation is explained by the classical dipole scattering between the excitons which disturbs the exciton superradiance. The saturation is explained by a theory which takes the momentum dependence of the scattering potential into account. (C) 2000 Elsevier Science B.V. All rights reserved.