Enhanced Transport of Overdamped Particles in a Disordered Biased Periodic Potential

Abstract

This paper considers the diffusive properties of Brownian motion driven by an Ornstein-Uhlenbeck (OU) colored noise in a biased periodic potential corrugated by spatial disorders in the form of zero-mean random correlated potential. Through Langevin Monte-Carlo simulation, a giant enhancement diffusion is observed in a range of bias forces. Then, theoretical analysis based on the trajectory of a particle in the random correlated potential (RCP) is performed to investigate the transport phenomenon of particles. The effective diffusion coefficient is measured by the envelope width of the spatial distribution of the particle, and it becomes wider due to the emergence of the RCP. This is because the roughness of the potential causes a large proportion of the test particles to be locked or trapped. Furthermore, the positive-correlation characteristics of the OU noise are considered, and the optimal value of the effective diffusion coefficient is discussed.