Nonequilibrium Prethermal States in a Two-Dimensional Photon Fluid
Abuzarli, Murad and Cherroret, Nicolas and Bienaimé, Tom and Glorieux, Quentin

Phys. Rev. Lett. 129, 100602 (2022)

Phys. Rev. Lett. 129, 100602  (2022)

We report on the observation of a prethermal state in a nonequilibrium, two-dimensional fluid of light. Direct measurements of the first order coherence function of the fluid reveal the dynamical emergence of algebraic correlations, a quasi-steady-state with properties close to those of thermal superfluids. By a controlled increase of the fluctuations, we observe a crossover from algebraic to short-range (exponential) correlations. We interpret this phenomenon as a nonequilibrium precursor of the Kosterlitz-Thouless transition.