1. Collective dynamics of dense systems of active polar disks in circular confinement
- Author
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Tang, Weizhen, Zheng, Yating, Shee, Amir, Lin, Guozheng, Han, Zhangang, Romanczuk, Pawel, and Huepe, Cristián
- Subjects
Condensed Matter - Soft Condensed Matter - Abstract
We study the emerging collective states in a simple mechanical model of a dense group of self-propelled polar disks confined within a circular arena. Each disk has its center of rotation located at a distance R behind its centroid, so its central linear contact forces can produce torques leading to mutual alignment. Each disk is thus affected by this mutual alignment to its neighbors' orientations and by self-alignment (resulting from disk-substrate interactions) towards the sum of forces over it. The effect of both alignment mechanisms produces a variety of collective states combining high-frequency localized circular oscillations with low-frequency milling around the center of the arena, in fluid or solid regimes. We consider cases with small/large R values, isotropic/anisotropic disk-substrate damping, smooth/rough arena boundaries, different densities, and multiple systems sizes, showing that the identified emergent collective states are robust, generic, and potentially observable in real-world natural or artificial systems., Comment: 13 pages, 9 figures
- Published
- 2024