title: Effective interactions in active Brownian suspensions.
abstract: Active colloids exhibit persistent motion, which can lead to motility-induced phase separation (MIPS). However, there currently exists no microscopic theory to account for this phenomenon. We report a first-principles theory, free of fit parameters, for active spherical colloids, which shows explicitly how an effective many-body interaction potential is generated by activity and how this can rationalize MIPS. For a passively repulsive system the theory predicts phase separation and pair correlations in quantitative agreement with simulation. For an attractive system the theory shows that phase separation becomes suppressed by moderate activity, consistent with recent experiments and simulations, and suggests a mechanism for reentrant cluster formation at high activity.
authors.affiliation: Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland.
authors.forename: T F F
authors.initials: TF
authors.lastname: Farage
authors.affiliation: Theoretische Physik II, Physikalisches Institut, Universität Bayreuth, D-95440 Bayreuth, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Krinninger
authors.affiliation: Department of Physics, University of Fribourg, CH-1700 Fribourg, Switzerland.
authors.forename: J M
authors.initials: JM
authors.lastname: Brader
mesh_terms: D008956:Models, Chemical; D009038:Motion; D044367:Phase Transition; D013269:Stochastic Processes; D013535:Suspensions / Q000737:chemistry*
chemical_list: D013535:Suspensions