Ordered Dissipative Structures in Exciton Systems in Semiconductor Quantum Wells

TL;DR

This paper develops a phenomenological theory to explain exciton condensation phenomena in semiconductor quantum wells, including luminescence ring formation, fragmentation, and localized condensed phase islands under inhomogeneous excitation.

Contribution

It introduces a new theoretical framework for exciton condensation in inhomogeneous conditions, addressing ring development, fragmentation, and defect-induced localization in quantum wells.

Findings

Explains formation of luminescence rings and their fragmentation.

Shows possibility of localized condensed phase islands due to defects.

Analyzes exciton density distribution for multiple excitation spots.

Abstract

A phenomenological theory of exciton condensation in conditions of inhomogeneous excitation is proposed. The theory is applied to the study of the development of an exciton luminescence ring and the ring fragmentation at macroscopical distances from the central excitation spot in coupled quantum wells. The transition between the fragmented and the continuous ring is considered. With assumption of a defect in the structure, a possibility of a localized island of the condensed phase in a fixed position is shown. Exciton density distribution is also analyzed in the case of two spatially separated spots of the laser excitation.