Numerical Study of Biased Brownian Motion in Narrow Asymmetric Channel with Anisotropy

Recently experiments [Zheng Peng and Kiwing To, PRE 94, 022902 (2016)] showed that a Brownian particle in a narrow channel with asymmetric walls maybe biased to drift uni-directionaly by the presence of anisotropy in the longitudinal and transverse directions. Here we perform Brownian dynamics simulations of the experiments to study the physics behind the phenomenon. We verify that the driving force of the drift is indeed originated by the anisotropy the channel walls. Furthermore, the drift velocity is proportional to the mean-square velocity in the transverse direction.