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RESEARCH PRODUCT
Dynamical mean-field theory and weakly non-linear analysis for the phase separation of active Brownian particles
Julian BialkéThomas SpeckAndreas M. MenzelHartmut Löwensubject
PhysicsPhase transitionStatistical Mechanics (cond-mat.stat-mech)General Physics and AstronomyFOS: Physical sciencesCondensed Matter - Soft Condensed MatterPolarization (waves)Nonlinear systemDynamical mean field theoryActive phaseSoft Condensed Matter (cond-mat.soft)Statistical physicsPhysical and Theoretical ChemistryCondensed Matter - Statistical MechanicsBrownian motiondescription
Recently, we have derived an effective Cahn-Hilliard equation for the phase separation dynamics of active Brownian particles by performing a weakly non-linear analysis of the effective hydrodynamic equations for density and polarization [Speck et al., Phys. Rev. Lett. 112, 218304 (2014)]. Here, we develop and explore this strategy in more detail and show explicitly how to get to such a large-scale, mean-field description starting from the microscopic dynamics. The effective free energy emerging from this approach has the form of a conventional Ginzburg-Landau function. On the coarsest scale, our results thus agree with the mapping of active phase separation onto that of passive fluids with attractive interactions through a global effective free energy (motility-induced phase transition). Particular attention is paid to the square-gradient term necessary for the phase separation kinetics. We finally discuss results from numerical simulations corroborating the analytical results.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2015-03-29 |