Hyperuniformity in active fluids reshapes nucleation and capillary-wave dynamics

TL;DR

This paper studies how hyperuniformity in active fluids alters nucleation processes and capillary-wave behavior, revealing nonequilibrium effects and breakdown of detailed balance.

Contribution

It introduces a framework to analyze nucleation in hyperuniform active fluids, highlighting the role of a nonequilibrium quasi-potential and nonreciprocal dynamics.

Findings

Nucleation governed by a nonequilibrium quasi-potential instead of reversible work.

Nucleation probability lacks the usual surface and volume separation due to hyperuniform fluctuations.

Capillary waves show a breakdown of detailed balance caused by nonreciprocal dynamics.

Abstract

While nucleation in typical active and driven fluids often appears equilibrium-like, striking departures emerge when large-scale fluctuations are strongly suppressed. Here, we investigate nucleation in nonequilibrium hyperuniform fluids by projecting the full density-field dynamics onto relevant collective variables. We demonstrate that nucleation is governed by a nonequilibrium quasi-potential rather than the reversible work of formation. Surprisingly, because of the reduced hyperuniform fluctuations, the nucleation probability no longer separates into the usual surface and volume contributions. Furthermore, accounting for capillary waves reveals a clear breakdown of detailed balance driven by nonreciprocal dynamics. More broadly, our framework can be readily extended to identify nonequilibrium signatures in conventional active fluids.