Collective Circular Swimmer-Like Behavior of Chiral Active Nematics Confined to a Circular Cavity

Abstract

Understanding the development of collective motion of chiral active nematics is a relevant issue in physics and biology. Here, we perform molecular dynamics simulations of dilute ensembles of active chiral elongated particles confined to a two-dimensional circular cavity under both radial and tangential boundary conditions. In addition to interparticle isotropic Lennard-Jones and anisotropic Maier-Saupe-like interactions, the active nematic particles exert self-propelling forces and torques. We show that active nematic particles form compact clusters which acquire a circular swimmer-like behavior with the clockwise or counterclockwise directions of their rotations being defined by the chiralities of individual particles. The vectors associated with the average orientation of clusters and the velocity of their center of mass rotate synchronously. Further, in a mixture of particles having opposite chiralities, they self-organize and separate into clusters with well-defined chiralities. Our results shed light on the physical mechanisms underlying the development of self-organization in chiral active nematic matter.