Size distribution and concentration of islands of a condensed exciton phase in a quantum well

Abstract

A theory describing the formation of condensed-phase regions at a high concentration of excitons in a quantum well is constructed. The condensed phase can be either an exciton or an electron-hole liquid. When the condensed phase and exciton gas coexist, islands of the condensed phase have the shape of disks. A simultaneous solution to the kinetic equation (determining the island sizes) and the diffusion equation for excitons outside the islands is obtained for stationary pumping. It is assumed that the exciton gas is nondegenerate outside the islands. The mutual influence of islands through the concentration fields of excitons is taken into account assuming that the mean radius of islands substantially exceeds the mean distance between them. The radius distribution and concentration of islands are determined as functions of the rate of exciton production and the parameters of the system. It is found that the radius distribution of islands is broadened near the threshold of formation of the condensed phase.