Collective Motion of Self-Propelled Particles with Memory

Ken H. Nagai (1) , Yutaka Sumino (2) , Raul Montagne (3) , Igor S. Aranson (4) , Hugues Chaté (5, 6, 7)

1 JAIST - Japan Advanced Institute of Science and Technology
2 Department of Applied Physics, The University of Tokyo
3 UFRPE /PADR
4 Materials Science Division
5 LPTMC - Laboratoire de Physique Théorique de la Matière Condensée
6 CSRC - Beijing Computational Science Research Center [Beijing]
7 SPEC - UMR3680 - Service de physique de l'état condensé

We show that memory, in the form of underdamped angular dynamics, is a crucial ingredient for the collective properties of self-propelled particles. Using Vicsek-style models with an Ornstein-Uhlenbeck process acting on angular velocity, we uncover a rich variety of collective phases not observed in usual overdamped systems, including vortex lattices and active foams. In a model with strictly nematic interactions the smectic arrangement of Vicsek waves giving rise to global polar order is observed. We also provide a calculation of the effective interaction between vortices in the case where a telegraphic noise process is at play, explaining thus the emergence and structure of the vortex lattices observed here and in motility assay experiments.

Domains: Physics [physics]

Ken H. Nagai, Yutaka Sumino, Raul Montagne, Igor S. Aranson, Hugues Chaté. Collective Motion of Self-Propelled Particles with Memory. Physical Review Letters, 2015, 114, pp.168001. ⟨10.1103/PhysRevLett.114.168001⟩. ⟨cea-01367162⟩