Postquench prethermalization in a disordered quantum fluid of light

TL;DR

This paper investigates how a disordered, interacting quantum light field propagates through a nonlinear fiber, revealing that decoherence spreads in a light-cone manner and leads to prethermalization with unique disorder-related features.

Contribution

It introduces a novel study of disorder and interaction quenches in quantum light propagation, demonstrating light-cone spreading of decoherence and disorder-induced prethermalization.

Findings

Decoherence spreads in a light-cone fashion after the quench.

The quantum system exhibits prethermalization with disorder-specific features.

Disorder is generated via cross-phase modulation with a randomized classical field.

Abstract

We study the coherence of a disordered and interacting quantum light field after propagation along a nonlinear optical fiber. Disorder is generated by a cross-phase modulation with a randomized auxiliary classical light field, while interactions are induced by self-phase modulation. When penetrating the fiber from free space, the incoming quantum light undergoes a disorder and interaction quench. By calculating the coherence function of the transmitted quantum light, we show that the decoherence induced by the quench spreads in a light-cone fashion in the nonequilibrium many-body quantum system, leaving the latter prethermalize with peculiar features originating from disorder.