Deformable active nematic particles and emerging edge currents in circular confinements

TL;DR

This paper introduces a microscopic field theoretical model for active nematic particles, revealing how varying activity levels induce different collective behaviors, including self-spinning, translation, and edge currents within circular confinements.

Contribution

It presents a novel theoretical framework linking particle shape deformation and activity to emergent collective phenomena in active nematics.

Findings

Intermediate activity causes asymmetric shapes and chiral self-spinning crystals.

Higher activity results in symmetric shapes and translational motion.

Edge currents and global rotation can disrupt crystalline order in confined systems.

Abstract

We consider a microscopic field theoretical approach for interacting active nematic particles. With only steric interactions the self-propulsion strength in such systems can lead to different collective behaviour, e.g., synchronized self-spinning and collective translation. The different behaviour results from the delicate interplay between internal nematic structure, particle shape deformation and particle-particle interaction. For intermediate active strength an asymmetric shape emerges and leads to chirality and self-spinning crystals. For larger active strength the shape is symmetric and translational collective motion emerges. Within circular confinements, depending on the packing fraction, the self-spinning regime either stabilizes positional and orientational order or can lead to edge currents and global rotation which destroys the synchronized self-spinning crystalline structure.