Enhanced diffusion of a tracer particle in a lattice model of a crowded active system

Abstract

Living systems at the sub-cellular, cellular, and multi-cellular level are often crowded systems that contain active particles. The active motion of these particles can also propel passive particles, which typically results in enhanced effective diffusion of the passive particles. Here we study the diffusion of a passive tracer particle in such a dense system of active crowders using a minimal lattice model incorporating particles pushing each other. We show that the model exhibits several regimes of motility and quantify the enhanced diffusion as a function of density and activity of the active crowders. Moreover, we demonstrate an interplay of tracer diffusion and clustering of active particles, which suppresses the enhanced diffusion. Simulations of mixtures of passive and active crowders show that a rather small fraction of active particles is sufficient for the observation of enhanced diffusion.

11 pages, 8 figures

References in corpus (4)

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• Non-universal tracer diffusion in crowded media of non-inert obstacles
• Liquid-Hextic-Solid Phase Transition of a Hard-Core Lattice Gas with Third Neighbor Exclusion
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Cited by in corpus (8)

• The Anomalous Transport of Tracers in Active Baths
• Long-time diffusion and energy transfer in polydisperse mixtures of particles with different temperatures
• Harvesting information to control non-equilibrium states of active matter
• Dynamical fluctuations of a tracer coupled to active and passive particles
• Dynamics of a Passive Droplet in Active Turbulence
• A Cold Tracer in a Hot Bath: In and Out of Equilibrium
• Statistical mechanics of a cold tracer in a hot bath
• Microcanonical ensemble out of equilibrium