Exciton-dephasing kinetics after coherent pulse excitation

A system of coherently excited weakly interacting excitons is investigated with respect to its coherent and incoherent dynamics. Both the mean-field terms and the scattering terms are calculated on a microscopic level including the contribution of the anomalous functions. In this framework, the transition from coherent to incoherent excitons is studied. At high excitation densities near the critical density for a Bose-Einstein condensation a pronounced slowing down of the dephasing is obtained.