The origin of KPZ-scaling in arrays of polariton condensates

TL;DR

This paper explains how KPZ scaling emerges in polariton condensates by linking Goldstone mode fluctuations to the observed power laws in phase correlations, supported by simulations and theory.

Contribution

It reveals that Goldstone mode fluctuations due to spontaneous symmetry breaking cause KPZ scaling in polariton condensates, connecting microscopic parameters to coherence properties.

Findings

Goldstone mode fluctuations lead to KPZ scaling in polariton condensates.

Numerical and analytical results confirm the connection between Goldstone dynamics and KPZ exponents.

The study links microscopic parameters of polariton arrays to their emitted light's coherence.

Abstract

This work investigates the origin of Kardar-Parisi-Zhang (KPZ) scaling in the phase dynamics of one-dimensional and two-dimensional polariton condensates. We demonstrate that the key mechanism leading to the observed power laws for the first-order correlation function $g^{(1)}$ is the fluctuation of the population of Goldstone modes, which arise due to the spontaneous breaking of $U(1)$ symmetry. Numerical simulations and analytical theory confirm that the critical exponents describing the KPZ universality class directly follow from the dynamics of Goldstone excitations. Our results establish a direct connection between the microscopic parameters of arrays of exciton-polariton condensates and the coherent properties of the light they emit.