Non-Markovian stochastic Gross-Pitaevskii equation for the exciton-polariton Bose-Einstein condensate

TL;DR

This paper introduces a non-Markovian Gross-Pitaevskii equation to model exciton-polariton condensates, revealing temperature-induced phase transitions, decoherence, and spectral broadening in the condensate.

Contribution

It presents a novel non-Markovian equation incorporating spatial noise to describe condensate formation and transition dynamics in exciton-polariton systems.

Findings

Transition from ordered to disordered phase with temperature

Condensate population decreases as temperature rises

Spectral density broadens indicating decoherence

Abstract

In this paper, a non-Markovian Gross-Pitaevskii equation is proposed to describe the formation of a condensate in an exciton-polariton system under incoherent pumping. By introducing spatially delta-correlated noise terms, we observe a transition from a spatially ordered phase to a disordered one as the temperature increases. In course of this process, the population of the condensate is significantly reduced. Irregularly located separate dense spots of condensate above the transition temperature are revealed. Using the Gabor transform, it is shown that, with increasing temperature, the condensate decoheres, that is accompanied by the transition from narrowband to broadband spectral density.