Ordered structures of exciton condensed phases in the presence of an inhomogeneouspotential

Abstract

A theory of the separation of a system of indirect excitons into a condensed and a gaseousphase with the formation of regular patterns of alternating phases in inhomogeneousexternal fields is developed. The model of spinodal decomposition of phase transitions,generalized for systems of unstable particles, is used. The theory is applied to the study ofthe non-uniform distribution of the exciton density in a double quantum wellunder a slot cut in a metallic electrode. It is shown that in a certain range ofexciton generation rates a chain of light-emitting islands periodically localizedalong the slot is developed. With increasing width of the slot, the chain splitsinto two parallel chains shifted by a half period with respect to each other. Bycreating a biased external potential along the slot, the periodical pattern couldbe forced to move along the slot. The effect of the motion of the islands shouldmanifest itself as time oscillations of the intensity of the light emitted from a fixedpoint.