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.