Ratchet universality in the presence of thermal noise

TL;DR

This paper demonstrates that directed ratchet transport in overdamped Brownian particles can be controlled by a biharmonic force, with temperature effects interpreted as an effective change in potential barriers, revealing a universal behavior across symmetric potentials.

Contribution

It introduces a universal framework for controlling ratchet transport via symmetry-breaking and impulse maximization, accounting for thermal noise effects.

Findings

Directed transport is controllable by biharmonic forcing.

Thermal noise acts as an effective potential barrier change.

Universal behavior applies to any symmetric periodic potential.

Abstract

We show that directed ratchet transport of a driven overdamped Brownian particle subjected to a spatially periodic and symmetric potential can be reliably controlled by tailoring a biharmonic temporal force, in coherence with the degree-of-symmetry-breaking mechanism. We demonstrate that the effect of finite temperature on the purely deterministic ratchet scenario can be understood as an \textit{effective noise-induced change} of the potential barrier which is in turn controlled by the degree-of-symmetry-breaking mechanism. Remarkably, we find that the same universal scenario holds for any symmetric periodic potential, while optimal directed ratchet transport occurs when the impulse transmitted (spatial integral over a half-period) by the symmetric spatial force is maximum.