Collective motion of active particles exhibiting non-reciprocal orientational interactions
Abstract
We present a Brownian dynamics study of a 2D bath of active particles interacting among each other through usual steric interactions and, additionally, via non-reciprocal avoidant orientational interactions. We motivate them by the fact that the two flagella of the alga Chlamydomonas interact sterically with nearby surfaces such that a torque acts on the alga. As expected, in most cases such interactions disrupt the motility-induced particle clustering in active baths. Surprisingly, however, we find that the active particles can self-organize into collectively moving flocks if the range of non-reciprocal interactions is close to that of steric interactions. We observe that the flocking motion can manifest itself through a variety of structural forms, spanning from single dense bands to multiple moderately-dense stripes, which are highly dynamic. The flocking order parameter is found to be only weakly dependent on the underlying flock structure. Together with the variance of the local-density distribution, one can clearly group the flocking motion into the two separate band and dynamic-stripes states.
- Publication:
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Scientific Reports
- Pub Date:
- November 2022
- DOI:
- 10.1038/s41598-022-23597-9
- arXiv:
- arXiv:2204.06089
- Bibcode:
- 2022NatSR..1219437K
- Keywords:
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- Condensed Matter - Soft Condensed Matter
- E-Print:
- 10 pages, 6 figures