Activated Drift Motion of a Classical Particle With a Dynamical Pinning Effect

TL;DR

This paper introduces a one-dimensional trap model for a classical particle with aging effects, revealing how dynamical pinning influences velocity-force behavior and leads to sublinear dynamics and strong fluctuations.

Contribution

It presents a novel trap model incorporating aging effects and studies its impact on driven particle dynamics and velocity-force characteristics.

Findings

Dynamical pinning suppresses linear response at low velocities.

Broad trapping time distribution causes threshold or sublinear dynamics.

Intermediate velocities induce strong fluctuation regimes.

Abstract

A one dimensional trap model for a thermally activated classical particle is introduced to simulate driven dynamics in presence of "ageing" effects. The depth of each trap increases with the time elapsed since the particle has fallen into it. The consequences of this dynamical pinning are studied, and velocity-force characteristics are numerically obtained. A special attention is paid to the situation where the particle is pulled with a spring to ensure a finite average velocity. In the low velocity regime, the presence of a broad distribution of trapping times leads to suppression of linear response, replaced by a threshold or by sublinear dynamics. A regime of strong fluctuations is obtained when the particle is driven at intermediate velocities.