Emergent States in Systems of Chiral Self-Propelled Rods

TL;DR

This paper investigates chiral self-propelled particles with nematic interactions, revealing various flocking states through theoretical analysis and simulations, including homogeneous and microflock phases, emphasizing careful simulation techniques.

Contribution

It introduces a comprehensive mean field kinetic theory for chiral self-propelled rods and confirms predicted phases with novel simulation methods.

Findings

Identification of homogeneous nematic phase at low frequencies

Discovery of microflock pattern phase at higher frequencies

Development of a non-standard simulation technique to avoid artifacts

Abstract

We study inherently chiral self-propelled particles, self-rotating at a fixed frequency, in two dimensions, subjected to nematic alignment interactions and rotational noise. By means of both, homogeneous and spatially resolved mean field kinetic theory, we identify various different flocking states. We confirm the presence of the predicted phases using agent-based simulations, in particular, an homogeneous nematic phase at low frequencies, followed by a microflock pattern phase at larger frequencies, characterized by finite-size nematic clusters. We emphasize that special care has to be taken within the simulations in order to avoid artifacts, and present a non-standard simulation technique in order to avoid them.