Active and passive particles : Modeling beads in a bacterial bath

Guillaume Grégoire (1) , Hugues Chaté (2) , Yuhai Tu (3)

1 MSC - Matière et Systèmes Complexes
2 SPEC - UMR3680 - Service de physique de l'état condensé
3 IBM Watson Research Center

A simple model for the motion of passive particles in a bath of active, self-propelled ones is introduced. It is argued that this approach provides the correct framework within which to cast the recent experimental results obtained by Wu and Libchaber [Phys Rev. Lett. 84, 3017 (2000)] for the diffusive properties of polystyrene beads displaced by bacteria suspended in a two-dimensional fluid film. Our results suggest that superdiffusive behavior should indeed be generically observed in the transition region marking the onset of collective motion.

Domaines: Autre [cond-mat.other]

Guillaume Grégoire, Hugues Chaté, Yuhai Tu. Active and passive particles : Modeling beads in a bacterial bath. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2001, 64 (1), pp.011902. ⟨10.1103/PhysRevE.64.011902⟩. ⟨hal-01053517⟩