Memory-induced current reversal of Brownian motors

TL;DR

This paper investigates how memory effects in a non-Markovian environment can cause current reversal in Brownian motors, revealing new insights into microscopic systems out of thermal equilibrium.

Contribution

It introduces a model of a Brownian ratchet in a correlated thermal bath and demonstrates memory-induced current reversal and dynamical localization effects.

Findings

Memory induces current reversal in Brownian motors.

Memory causes dynamical localization of trajectories.

Effective mass approximation explains the phenomena.

Abstract

Kinetics of biological motors such as kinesin or dynein is notably influenced by viscoelastic intracellular environment. The characteristic relaxation time of the cytosol is not separable from the colloidal timescale and therefore their dynamics is inherently non-Markovian. In this paper we consider a variant of a Brownian motor model, namely a Brownian ratchet immersed in a correlated thermal bath and analyze how memory influences its dynamics. In particular, we demonstrate the memory-induced current reversal effect and explain this phenomenon by applying the effective mass approximation as well as uncovering the memory-induced dynamical localization of the motor trajectories in the phase space. Our results reveal new aspects of the role of memory in microscopic systems out of thermal equilibrium.