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arXiv · 1609.03483

Generalized Thermodynamics of Phase Equilibria in Scalar Active Matter

Alexandre P. Solon·Joakim Stenhammar·Michael E. Cates·Yariv Kafri·Julien Tailleur
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Abstract

Motility-induced phase separation (MIPS) arises generically in fluids of self-propelled particles when interactions lead to a kinetic slowdown at high densities. Starting from a continuum description of scalar active matter, akin to a generalized Cahn-Hilliard equation, we give a general prescription for the mean densities of coexisting phases in flux-free steady states that amounts, at a hydrodynamics scale, to extremizing an effective free energy. We illustrate our approach on two well-known models: self-propelled particles interacting either through a density-dependent propulsion speed or via direct pairwise forces. Our theory accounts quantitatively for their phase diagrams, providing a unified description of MIPS.

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BibTeXRIS

Alexandre P. Solon, Joakim Stenhammar, Michael E. Cates, Yariv Kafri, Julien Tailleur. 2018-02-21. Generalized Thermodynamics of Phase Equilibria in Scalar Active Matter. https://doi.org/10.1103/physreve.97.020602

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