The Effect of Pinning on Drag in Coupled One-Dimensional Channels of Particles

TL;DR

This study investigates how quenched disorder affects drag in coupled one-dimensional particle channels, revealing complex dynamical phases and decoupling phenomena influenced by pinning strength and distribution.

Contribution

It introduces a model analyzing the impact of pinning on drag in coupled 1D channels, uncovering diverse dynamical phases and phase transitions not previously characterized.

Findings

Pinning induces a variety of dynamical phases observable in velocity-force curves.

Quenched disorder can cause a pinned phase in both channels, even if only one is pinned.

Increasing pinning strength can lead to channel decoupling and reentrant pinning in the undriven channel.

Abstract

We consider a simple model for examining the effects of quenched disorder on drag consisting of particles interacting via a Yukawa potential that are placed in two coupled one-dimensional channels. The particles in one channel are driven and experience a drag from the undriven particles in the second channel. In the absence of pinning, for a finite driving force there is no pinned phase; instead, there are two dynamical regimes of completely coupled or locked flow and partially coupled flow. When pinning is added to one or both channels, we find that a remarkably rich variety of dynamical phases and drag effects arise that can be clearly identified by features in the velocity force curves. The presence of quenched disorder in only the undriven channel can induce a pinned phase in both channels. Above the depinning transition, the drag on the driven particles decreases with increasing pinning strength, and for high enough pinning strength, the particles in the undriven channel reach a reentrant pinned phase which produces a complete decoupling of the channels. We map out the dynamic phase diagrams as a function of pinning strength and the density of pinning in each channel. Our results may be relevant for understanding drag coupling in 1D Wigner crystal phases, and the effects we observe could also be explored using colloids in coupled channels produced with optical arrays, vortices in nanostructured superconductors, or other layered systems where drag effects arise.