Phase Separation Kinetics in a Polar Active Field Model

TL;DR

This paper studies phase separation in a polar active field model, revealing a new accelerated domain growth regime of approximately t^{0.6} due to advection effects, supported by analytical and simulation evidence.

Contribution

It introduces a novel t^{0.6} growth regime in polar active phase separation, explaining its origin through advection and defect formation, and demonstrates its robustness.

Findings

Discovery of a t^{0.6} growth regime in polar active phase separation.

Analytical explanation linking advection to defect creation and domain compression.

Validation of the regime's robustness across model variations.

Abstract

A milestone of phase separation kinetics is the emergence of universal power laws $\sim t^{1/z}$ governing the domain growth evolution. We investigate a phase-separating polar active model comprising a scalar density field with an advective coupling to a polarization field. Our analysis reveals a novel $\sim t^{0.6}$ regime, which agrees well with the accelerated growth recently observed in simulations of polar active particles. We provide analytical arguments to explain how advection facilitates the creation of topological defects and compresses the domains leading to faster growth. We also show that the $\sim t^{0.6}$ regime is robust to several model generalizations.