Anti-trapping of indirect excitons by a current filament.

In order to explain the photoluminescence (PL) of indirect excitons collected from localized spots in experiments with a defocused laser excitation of coupled quantum wells (QWs), we model the in-plane carrier transport and charge distribution with a set of drift-diffusion, Poisson and thermalization equations. The quantum statistical corrections are included in our description via a generalized Einstein relationship and quantum mass action law. The PL spots are attributed to transverse current filaments crossing the structure and injecting electrons in the coupled QWs. The accumulated electron charge forms an anti-trap for indirect excitons. Our model quantitatively reproduces the whole set of the relevant experimental data.