Rectification of motion in nonlinear media with asymmetric random drive

TL;DR

This paper studies how particles in nonlinear media with asymmetric random driving forces exhibit directed motion, analyzing the effects of nonlinearity, asymmetry, and stochastic direction changes on their transport properties.

Contribution

It introduces a model for particle motion in nonlinear media driven by asymmetric dichotomic noise, providing analytical calculations of current and fluctuations.

Findings

Directed particle flow arises from asymmetric drive and nonlinear friction.

Stationary current and variance depend on nonlinearity and drive asymmetry.

In two dimensions, stochastic changes in drive direction lead to diffusive motion.

Abstract

We consider moving particles in media with nonlinear friction and drive them by an asymmetric dichotomic Markov process. Due to different energy dissipations, during the forward and backward stroke, we obtain a mean non-vanishing directed flow of the particles. Starting with the stationary velocity distribution, we calculate the stationary current of particles, the variance and the relative variance in dependence on the degree of nonlinearity of the friction, on the asymmetry and for different strengths of friction. In two dimensions the particle performs diffusional motion, if in addition the direction of the asymmetric drive changes stochastically.