Negative Differential Mobility in Interacting Particle Systems

TL;DR

This paper introduces a new mechanism for negative differential mobility in many-particle systems caused by the slowing down of non-driven particles due to interactions, demonstrated through exact solutions of various models.

Contribution

It proposes a novel interaction-based mechanism for NDM and provides exact solutions for several driven diffusive systems illustrating this effect.

Findings

Demonstrates NDM arising from slowed non-driven particles due to interactions

Provides exact steady-state solutions for multiple driven diffusive models

Shows that the mechanism leads to observable NDM in these systems

Abstract

Driven particles in presence of crowded environment, obstacles or kinetic constraints often exhibit negative differential mobility (NDM) due to their decreased dynamical activity. We propose a new mechanism for complex many-particle systems where slowing down of certain {\it non-driven} degrees of freedom by the external field can give rise to NDM. This phenomenon, resulting from inter-particle interactions, is illustrated in a pedagogical example of two interacting random walkers, one of which is biased by an external field while the same field only slows down the other keeping it unbiased. We also introduce and solve exactly the steady state of several driven diffusive systems, including a two species exclusion model, asymmetric misanthrope and zero-range processes, to show explicitly that this mechanism indeed leads to NDM.