Escape of an Active Ring from an Attractive Surface: Behaving Like a Self-Propelled Brownian Particle

TL;DR

This study investigates how a flexible active ring escapes from an attractive surface, revealing two distinct mechanisms influenced by activity levels and potential shape, and demonstrating that it can be modeled as a self-propelled Brownian particle.

Contribution

It introduces a detailed analysis of escape mechanisms for active rings, showing their effective modeling as self-propelled Brownian particles under various conditions.

Findings

Escape mechanisms depend on persistence time and activity level.

Escape time varies with the shape of the potential barrier.

Biased propulsion along the ring's contour increases escape difficulty.

Abstract

Escape of active agents from metastable states is of great interest in statistical and biological physics. In this study, we investigate the escape of a flexible active ring, composed of active Brownian particles, from a flat attractive surface using Brownian dynamics simulations. To systematically explore the effects of activity, persistence time, and the shape of attractive potentials, we calculate escape time and effective temperature. We observe two distinct escape mechanisms: Kramers-like thermal activation at small persistence times and the maximal force problem at large persistence time, where escape time is determined by persistence time. The escape time explicitly depends on the shape of the potential barrier at high activity and large persistence time. Moreover, when the propulsion force is biased along the ring's contour, escape becomes more difficult and is primarily driven by thermal noise. Our findings highlight that, despite its intricate configuration, the active ring can be effectively modeled as a self-propelled Brownian particle when studying its escape from a smooth surface.