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

TL;DR

This paper proposes a method to extend the lifetime of two-dimensional direct excitons in layered heterostructures, enabling the observation of Bose-Einstein condensation at higher temperatures through suppressed radiative decay.

Contribution

It introduces a novel approach to suppress exciton radiative decay in GaAs quantum wells within photonic heterostructures, facilitating high-temperature exciton condensation.

Findings

Radiative decay of excitons is strongly suppressed in the proposed structure.

A Berezinskii-Kosterlitz-Thouless crossover is predicted at finite exciton densities.

Photoluminescence intensity increases significantly below critical temperatures.

Abstract

We propose a way to increase the lifetime of two-dimensional direct excitons and show the possibility to observe their macroscopically coherent state at high temperatures. For a single GaAs quantum well embedded in photonic layered heterostructures with subwavelength period, we predict 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. Below the estimated critical temperatures, drastic growth of the correlation length is shown to be accompanied by a manyfold increase of the photoluminescence intensity.