Transport coherence in a time-asymmetric rocked ratchet model

TL;DR

This paper investigates transport coherence in a time-asymmetric rocked ratchet model, revealing how spatial asymmetry, temperature, and drive amplitude influence particle transport and diffusion, with implications for understanding nonequilibrium systems.

Contribution

It introduces a detailed analysis of transport coherence in a sawtooth ratchet with temporal asymmetry, highlighting novel temperature-dependent peaking behavior of the Peclet number.

Findings

Higher spatial asymmetry increases transport coherence.

Diffusion minimizes where current peaks, indicating optimal transport conditions.

Transport coherence peaks at specific temperatures and diminishes at high temperatures.

Abstract

We study the dynamics of an over damped Brownian particle in a saw tooth potential in the presence of a temporal asymmetric driving force. We observe that in the deterministic limit, the transport coherence, which is determined by a dimensionless quantity called Peclet number, $Pe$ is quite high for larger spatial asymmetry in the ratchet potential. For all the regime of parameter space of this model, $Pe$ follows the nature of current like Stokes efficiency. Diffusion as a function of amplitude of drive shows a minimum exactly at which the current shows a maximum. Unlike the previously studied models, the $Pe$ as a function of temperature shows a peaking behavior and the coherence in transport decreases for high temperatures. In the nonadiabatic regime, the $Pe$ as a function of amplitude of drive decreases and the peak gets broader as a result the transport becomes unreliable.