From Flocking to Condensation: Collective Dynamics in Binary Chiral Active Matter

TL;DR

This paper investigates how mixtures of chiral microswimmers with opposite chirality exhibit diverse collective behaviors, including flocking and condensation, depending on chirality strength and self-propulsion, revealing complex phase transitions.

Contribution

It introduces a detailed analysis of phase behavior in binary chiral active matter, highlighting the competition between chirality and self-propulsion as a key factor.

Findings

Weak chirality leads to flocking of mixed particles

Intermediate chirality induces phase-separated condensates

Self-propulsion speed influences phase stability and transitions

Abstract

Many microswimmers are inherently chiral, and this chirality can introduce fascinating behaviors in a collection of microswimmers. The dynamics become even more intriguing when two types of microswimmers with distinct chirality are mixed. Our study examines a mixture of self-propelled particles with opposite chirality, investigating how the system's characteristics evolve as the magnitude of chirality is varied. In weakly chiral systems, the particles exhibit similar behavior, leading to a globally flocking phase where both types of particles are well-mixed. However, in an intermediate range of chirality, the condensates of different particles are formed as a result of a competition between chirality and self-propulsion. This competition results in interesting phases within the system. We explore the characteristics of these distinct phases in detail, focusing on the roles of self-propulsion speed and chirality.