Hydrodynamic Switching Fronts Polarize Deformable Particle Trains
Abstract
We show that propagating switching fronts mediate directional state transmission and polarity selection in a passive many-body suspension. In confined trains of slipper-shaped deformable particles in Poiseuille flow, this behavior originates from directionally biased switching between neighboring particles: owing to the fore-aft asymmetry of the slipper, an upstream particle drives switching of its downstream neighbor more effectively than in the reverse direction. A local transition from an opposite-sign pair to a same-sign pair therefore launches a streamwise front that relays the inclination sign from particle to particle. A minimal coarse-grained model with local bistability and directional coupling captures front propagation and arrest. In periodic trains, the fronts coarsen into a uniformly polarized state, whereas in long open trains they arrest and leave persistent polarized domains. Our results point to local bistability and directional coupling as a route to collective polarization in passive many-body systems.
Cite
@article{arxiv.2604.05925,
title = {Hydrodynamic Switching Fronts Polarize Deformable Particle Trains},
author = {Linzheng Huang and Hengdi Zhang and Zaicheng Zhang and Zaiyi Shen},
journal= {arXiv preprint arXiv:2604.05925},
year = {2026}
}
Comments
5 pages, 4 figures