Viscous Decoupling Transitions for Individually Dragged Particles in Systems with Quenched Disorder

TL;DR

This paper investigates how a single particle dragged through a disordered particle system experiences a viscous decoupling transition, where increased disorder strength can paradoxically increase its velocity, with observable signatures in velocity-force measurements.

Contribution

It introduces the concept of viscous decoupling transitions in particle systems with quenched disorder and explores how disorder influences particle dynamics in a novel way.

Findings

Decoupling transition occurs controlled by quenched disorder.

Increasing disorder strength can increase the particle's velocity.

The transition manifests as a clear feature in velocity-force curves.

Abstract

We show that when an individual particle is dragged through an assembly of other particles in the presence of quenched disorder, a viscous decoupling transition occurs between the dragged particle and the surrounding particles which is controlled by the quenched disorder. A counterintuitive consequence of this transition is that the velocity of the dragged particle can be increased by increasing the strength or density of the quenched disorder. The decoupling transition can also occur when the external drive on the dragged particle is increased, and is observable as a clear signature in the velocity-force response.