Phase alignment in a lattice of exciton-polaritonic Bose-Einstein condensates

TL;DR

This paper investigates how phase order in a lattice of exciton-polariton Bose-Einstein condensates depends on temperature, revealing a transition between ferromagnetic and antiferromagnetic arrangements and the stability of ordered patterns at high temperatures.

Contribution

It demonstrates the temperature-dependent phase ordering in exciton-polariton condensate lattices and shows their ability to maintain order at temperatures above the critical point for single condensates.

Findings

Phase order depends on temperature.

Transition from in-phase to checkboard order occurs with temperature change.

Ordered patterns persist at high temperatures due to suppressed modulational instability.

Abstract

Dynamics of exciton-polariton Bose-Einstein condensate is examined by means of the stochastic Gross-Pitaevskii equation including non-Markovian coupling to the excitonic reservoir. Attention is concentrated on properties of the condensate lattice created by laser beams providing incoherent pumping of the reservoir. It is shown that phase ordering of the lattice depends on temperature. The crossover between the in-phase (``ferromagnetic'') and the checkboard (``antiferromagnetic'') orders is accompanied by variation of the steady-state condensate density. Also it is shown that the condensate lattices can retain ordered pattern for temperatures which are much higher than the critical temperature of a single spot, probably due to suppression of the modulational instability.