Probing exciton condensation by speckled emission

Within Hartree-Fock theory for interacting excitons in coupled quantum wells, the influence of disorder on the exciton center of mass states is investigated. For low temperatures and high exciton densities, a dramatic spatial increase of the ground state wave function is predicted. This is reflected in a specific directional dependence of the emission intensity. A corresponding experiment is proposed which could add further evidence for spontaneous coherence and possibly condensation in dense exciton systems.