Transport driven by biharmonic forces: impact of correlated thermal noise

TL;DR

This paper investigates how correlated thermal noise affects the transport of an inertial Brownian particle driven by biharmonic forces, revealing regimes where noise correlation enhances or reduces particle velocity and causes current reversals.

Contribution

It introduces a detailed analysis of the impact of finite correlation time of thermal noise on Brownian transport, including regimes of velocity enhancement and current reversal, in a symmetric periodic system.

Findings

Longer noise correlation time can increase long-time particle velocity.

Extended correlation time can also decrease stationary velocity.

Thermal noise correlation induces multiple current reversals.

Abstract

We study an inertial Brownian particle moving in a symmetric periodic substrate, driven by a zero-mean biharmonic force and correlated thermal noise. The Brownian motion is described in terms of a Generalized Langevin Equation with an exponentially correlated Gaussian noise term, obeying the fluctuation-dissipation theorem. We analyse impact of non-zero correlation time of thermal noise on transport properties of the Brownian particle. We identify regimes where the increase of the correlation time intensifies long-time transport of the Brownian particle. The opposite effect is also found: longer correlation time reduces the stationary velocity of the particle. The correlation time induced multiple current reversal is detected. We reveal that thermal noise of non-zero correlation time can radically enhance long-time velocity of the Brownian particle in regimes where in the white noise limit the velocity is extremely small. All transport properties can be tested in the setup consisting of a resistively and capacitively shunted Josephson junction device.