Real-space condensation of reciprocal active particles driven by spontaneous symmetry breaking induced nonreciprocity

TL;DR

This paper reveals how spontaneous symmetry breaking in reciprocal active particle systems induces nonreciprocity, leading to real-space condensation and a new class of emergent physics driven by non-Hermitian effects.

Contribution

It demonstrates that nonreciprocity can emerge in reciprocal systems through spontaneous symmetry breaking, resulting in real-space condensation driven by non-Hermitian dynamics.

Findings

Emergent nonreciprocity influences system properties

Spontaneous symmetry breaking induces nonreciprocity

Real-space condensation of active particles occurs

Abstract

We investigate the steady-state and dynamical properties of a reciprocal many-body system consisting of self-propelled active particles with local alignment interactions that exists within a fan-shaped neighborhood of each particle. We find that the nonreciprocity can emerge in this reciprocal system once the spontaneous symmetry breaking is present, and the effective description of the system assumes a non-Hermitian structure that directly originates from the emergent nonreciprocity. This emergent nonreciprocity can impose strong influences on the properties the system. In particular, it can even drive a real-space condensation of active particles. Our findings pave the way for identifying a new class of physics in reciprocal systems that is driven by the emergent nonreciprocity.