Velocity condensation for magnetotactic bacteria

TL;DR

This paper investigates how different swimming strategies of magnetotactic bacteria influence their orientation behavior and collective motion, revealing that run-and-tumble dynamics can lead to velocity condensation and more effective collective behavior than active Brownian motion.

Contribution

It demonstrates that the swimming strategy significantly impacts orientation statistics and phase transition nature, highlighting the advantage of Le9vy run-and-tumble walks in collective motion.

Findings

Run-and-tumble dynamics cause velocity condensation with diverging orientation density.

The swimming strategy alters the phase transition to collective motion.

Le9vy walk strategies outperform active Brownian motion in triggering collective behavior.

Abstract

Magnetotactic swimmers tend to align along magnetic field lines against stochastic reorientations. We show that the swimming strategy, e.g. active Brownian motion versus run-and-tumble dynamics, strongly affects the orientation statistics. The latter can exhibit a velocity condensation whereby the alignment probability density diverges. As a consequence, we find that the swimming strategy affects the nature of the phase transition to collective motion, indicating that L\'evy run-and-tumble walks can outperform active Brownian processes as strategies to trigger collective behavior.