Active Brownian Motion in Two Dimensions
Urna Basu (LPTMS, Université Paris-Sud)
We study the dynamics of a single active Brownian particle in a two-dimensional harmonic trap. The active particle has an intrinsic time scale set by the rotational diffusion. The harmonic trap also induces a relaxational time-scale. We show that the competition between these two time scales leads to a nontrivial time evolution for the active Brownian particle. At short times a strongly anisotropic motion emerges leading to anomalous persistence properties. At long-times, the stationary position distribution in the trap exhibits two different behaviours: a Gaussian peak at the origin in the strongly passive limit and a delocalised ring away from the origin in the opposite strongly active limit. The predicted stationary behaviours in these limits are in agreement with recent experimental observations.
- Urna Basu, Satya N. Majumdar, Alberto Rosso and Grégory Schehr, Active Brownian Motion in Two Dimensions, preprint cond-mat.stat-mech arXiv:1804.09027