Bose condensation of direct excitons in an off-resonant cavity at elevated temperatures

Nina S. Voronova, Igor L. Kurbakov, Yurii E. Lozovik

Published 2018-08-01Version 1

We theoretically predict the possibility to observe a macroscopically coherent state of two-dimensional direct excitons at high temperatures, thanks to the dramatic increase of their lifetime in the cavities designed to inhibit exciton recombination. For a single GaAs quantum well embedded in a photonic layered heterostructure with subwavelength period, we show the exciton radiative decay to be strongly suppressed. Quantum hydrodynamic approach is used to study the Berezinskii-Kosterlitz-Thouless crossover in a finite exciton system with intermediate densities. As the system is cooled down below the estimated critical temperatures, the drastic growth of the correlation length is accompanied by a manyfold increase of the photoluminescence intensity.