Fluidization induced by Magnetic Interactions in Confined Active Matter

TL;DR

This study explores how magnetic interactions influence the behavior of confined active matter, demonstrating fluidization effects and new collective formations through experiments and simulations.

Contribution

It introduces the concept that magnetic interactions can fluidize active matter and induce novel collective behaviors in confined geometries.

Findings

Magnetic interactions inhibit clustering and delay its onset.

Magnetic dipolar interactions lead to train-like formations and vortices.

Magnetic active matter exhibits fluidization effects in confinement.

Abstract

We investigate magnetic active matter in confined geometries using both experiments with magnetic toy robots Hexbugs and simulations of elongated magnetic active Brownian particles in circular domains. Standard active particles tend to accumulate at boundaries, forming clusters even at relatively low densities. In the presence of magnetic interactions, we provide evidence for a fluidization effect that inhibits clustering and shifts its onset to higher packing fractions. Moreover, magnetic dipolar interactions give rise to novel collective behaviors, such as train-like formations, rotating pairs, and particle vortices.