Finite-size effects in two-photon correlations of exciton Bose-Einstein condensates

TL;DR

This paper investigates how finite-size effects influence two-photon correlations in exciton Bose-Einstein condensates, revealing deviations from traditional Bogoliubov theory predictions using quantum hydrodynamics.

Contribution

It introduces a quantum hydrodynamics approach to analyze finite-size impacts on two-photon emission in 2D exciton condensates, providing new insights beyond Bogoliubov theory.

Findings

Two-photon emission intensity scales differently with sample size than predicted by Bogoliubov theory.

Finite-size effects significantly alter two-photon correlation signals in exciton condensates.

The approach is applied to GaAs quantum wells and MoS₂ bilayers, demonstrating practical relevance.

Abstract

Accessing two-photon statistics via Hunbary Brown and Twiss (HBT)-type measurements is essential for investigations of excitonic Bose-condensates. In this paper we make use of quantum hydrodynamics in order to study the finite-size impact on the two-photon emission intensity of a 2D condensate of excitons. We use the developed approach to calculate the two-photon decay time of exciton condensate in GaAs quantum wells and MoS$_2$ bilayers. We demonstrate that the registered signal scales on the sample size in a qualitatively different manner than the Bogoliubov theory predicts.