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arXiv · 1307.4373

A continuum theory of phase separation kinetics for active Brownian particles

Joakim Stenhammar·Adriano Tiribocchi·Rosalind J. Allen·Davide Marenduzzo·Michael E. Cates
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Abstract

Active Brownian particles (ABPs), when subject to purely repulsive interactions, are known to undergo activity-induced phase separation broadly resembling an equilibrium (attraction-induced) gas-liquid coexistence. Here we present an accurate continuum theory for the dynamics of phase-separating ABPs, derived by direct coarse-graining, capturing leading-order density gradient terms alongside an effective bulk free energy. Such gradient terms do not obey detailed balance; yet we find coarsening dynamics closely resembling that of equilibrium phase separation. Our continuum theory is numerically compared to large-scale direct simulations of ABPs and accurately accounts for domain growth kinetics, domain topologies and coexistence densities.

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Joakim Stenhammar, Adriano Tiribocchi, Rosalind J. Allen, Davide Marenduzzo, Michael E. Cates. 2013-10-03. A continuum theory of phase separation kinetics for active Brownian particles. https://doi.org/10.1103/physrevlett.111.145702

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