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Updated: Oct 20, 2025

The Diffusion of Passive Tracers in Laminar Shear Flow
Published on: May 1, 2018
Attraction and condensation of driven tracers in a narrow channel
Asaf Miron1, David Mukamel1, Harald A Posch2
1Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 7610001, Israel.
Abstract:
Emergent bath-mediated attraction and condensation arise when multiple particles are simultaneously driven through an equilibrated bath under geometric constraints. While such scenarios are observed in a variety of nonequilibrium phenomena with an abundance of experimental and numerical evidence, little quantitative understanding of how these interactions arise is currently available. Here we approach the problem by studying the behavior of two driven "tracer" particles, propagating through a bath in a 1D lattice with excluded-volume interactions. We apply the mean-field approximation to analytically explore the mechanism responsible for the tracers' emergent interactions and compute the resulting effective attractive potential. This mechanism is then numerically shown to extend to a realistic model of hard driven Brownian disks confined to a narrow 2D channel.
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