Structure and Dynamics of Active Nematics under Circular Confinement - A Microscopic Simulation Study

Experimental work on circularly confined active nematics has shown interesting phenomena such as buckling, phase-separation and circulation, behaviors which are not readily captured in continuum models. Here, we use a particle-based computational model to study the dynamics of a confined active nematic, as a function of confinement size, activity, and the flexibility of the nematogens. We find that the behavior exhibited by this model qualitatively agrees with those of experiments. In particular, we find phase-separated circulation for sufficiently large activities, formation of defect dipoles for moderate activities and stiffnesses, and buckling at high stiffnesses and strong confinement.