Kardar-Parisi-Zhang universality in optically induced lattices of exciton-polariton condensates

TL;DR

This paper demonstrates that one-dimensional lattices of exciton-polariton condensates exhibit KPZ universality in their phase dynamics, confirmed through theoretical modeling and large-scale GPU simulations, revealing a transition from KPZ to EW regimes.

Contribution

The study derives a discrete complex-field model from the open-dissipative Gross-Pitaevskii equation and identifies conditions under which KPZ universality emerges in exciton-polariton condensate lattices.

Findings

KPZ scaling exponents are approximately 1/3 and 1/2 within the wedge region.

Simulations confirm the KPZ regime and the transition to Edwards-Wilkinson behavior outside it.

Large-scale GPU simulations validate the theoretical phase diagram predictions.

Abstract

We investigate space-time coherence in one-dimensional lattices of exciton-polariton condensates formed by fully reconfigurable non-resonant optical pumping. Starting from an open-dissipative Gross-Pitaevskii equation with deterministic reservoir kinetics and stochastic condensate noise, we derive a discrete complex-field model that incorporates coherent tunnelling, reservoir-mediated dissipative coupling and gain-saturation non-linearity. Adiabatic elimination of fast density fluctuations reveals a wedge-shaped region in the complex hopping plane where the coarse-grained phase dynamics reduces to the Kardar-Parisi-Zhang (KPZ) equation. By computing high-resolution phase diagrams of the temporal and spatial scaling exponents we pinpoint the boundaries separating the KPZ domain from the Edwards-Wilkinson (EW) regime. Large-scale graphics processing unit (GPU) simulations of chains containing up to $N=2000$ condensates confirm these predictions: inside the wedge the exponents converge to $\beta_{N}=\textbf{0.329}(3)\!\approx\!1/3$ and $\chi_{N}=\textbf{0.504}(4)\!\approx\!1/2$, whereas outside it the dynamics moves away from KPZ and ultimately flows toward the EW fixed point, although finite system size and finite observation time may yield intermediate effective exponents. These results pave the way to the implementation of ultrafast KPZ-simulators based on one-dimensional arrays of exciton-polariton condensates.