Synchronization crossover of polariton condensates in weakly disordered lattices

TL;DR

This paper investigates how weak local disorder affects the synchronization of polariton condensate lattices, revealing a transition from localized, unsynchronized states to delocalized, synchronized states with long-range order.

Contribution

It demonstrates the disorder-dependent crossover between localized and synchronized phases in polariton condensate lattices, highlighting implications for condensate array-based computation.

Findings

Synchronization depends strongly on weak disorder levels.

Transition from localized to delocalized fluid with increased tunneling.

Long-range order appears in the synchronized phase.

Abstract

We demonstrate that the synchronization of a lattice of solid-state condensates when inter-site tunnelling is switched on, depends strongly on the weak local disorder. This finding is vital for implementation of condensate arrays as computation devices. The condensates here are nonlinear bosonic fluids of exciton-polaritons trapped in a weakly disordered Bose-Hubbard potential, where the nearest neighboring tunneling rate (Josephson coupling) can be dynamically tuned. The system can thus be tuned from a localized to a delocalized fluid as the number density, or the Josephson coupling between nearest neighbors increases. The localized fluid is observed as a lattice of unsynchronized condensates emitting at different energies set by the disorder potential. In the delocalized phase the condensates synchronize, and long-range order appears, evidenced by narrowing of momentum and energy distributions, new diffraction peaks in momentum space, and spatial coherence between condensates. Our work identifies similarities and differences of this nonequilibrium crossover to the traditional Bose-glass to superfluid transition in atomic condensates.