Enhancing Mixing and Diffusion with Plastic Flow

TL;DR

This paper investigates how external driving and quenched disorder induce plastic flow in particle mixtures, leading to enhanced mixing and diffusion, with implications for controlling mixing in non-thermal systems.

Contribution

It demonstrates that external driving can induce plastic flow and mixing in phase-separating particle mixtures, a novel approach to controlling mixing without thermal fluctuations.

Findings

Plastic flow creates meandering, mixing channels.

External drive enhances transverse diffusion.

Mixing phase diagram mapped as a function of parameters.

Abstract

We use numerical simulations to examine two-dimensional particle mixtures that strongly phase separate in equilibrium. When the system is externally driven in the presence of quenched disorder, plastic flow occurs in the form of meandering and strongly mixing channels. In some cases this can produce a fast and complete mixing of previously segregated particle species, as well as an enhancement of transverse diffusion even in the absence of thermal fluctuations. We map the mixing phase diagram as a function of external driving and quenched disorder parameters.