Dynamics of Brownian particles in asymmetric confinement: Insights into Entropic Stochastic Resonance

TL;DR

This paper investigates how asymmetric confinement influences the thermodynamic response of overdamped Brownian particles under periodic driving, revealing effects on work done, entropy-energy transition, and introducing mean free flight time as a new ESR metric.

Contribution

It introduces the concept of asymmetric entropic bistable potential and proposes mean free flight time as a novel measure for Entropic Stochastic Resonance in such systems.

Findings

Asymmetric confinement reduces average work done.

Transition from energy-dominated to entropy-dominated states with transverse force.

Mean free flight time effectively characterizes ESR in asymmetric systems.

Abstract

We explore the effect of asymmetry in the thermodynamic response (work done) of an overdamped Brownian system driven by a time-periodic field when the particle is confined inside a bilobal irregular structure. The spatial irregularity of the asymmetric confinement results in an effective asymmetric entropic bistable potential along the direction of transport. We investigate how the frequency of the periodic field and the intensity of the noise impact the average work done, focusing on its potential as a key metric for examining Entropic Stochastic Resonance (ESR). The study highlights the impact of confinement asymmetry on reducing the average work done. Furthermore, we observe a transition of average work done from a state dominated by energy to one dominated by entropy, as we manipulate the magnitude of the transverse force. In addition, an alternative quantity called the mean free flight time ($T_{MFFT}$) is proposed to describe the ESR in the presence of asymmetry.