Dynamical mean-field theory and weakly non-linear analysis for the phase separation of active Brownian particles
arXiv:1503.08412 · doi:10.1063/1.4922324
Abstract
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 [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 (mobility-induced phase transition). Particular attention is paid to the square-gradient term necessary for the dynamics. We finally discuss results from numerical simulations corroborating the analytical results.
References in corpus (17)
- Novel type of phase transition in a system of self-driven particles
- Self-motile colloidal particles: from directed propulsion to random walk
- Motility-Induced Phase Separation
- Physics of Microswimmers - Single Particle Motion and Collective Behavior
- Meso-scale turbulence in living fluids
- Statistical Mechanics of Interacting Run-and-Tumble Bacteria
- When are active Brownian particles and run-and-tumble particles equivalent? Consequences for motility-induced phase separation
- Pressure and Phase Equilibria in Interacting Active Brownian Spheres
- Activity-induced phase separation and self-assembly in mixtures of active and passive particles
- Tuned, driven, and active soft matter
- Towards a 'Thermodynamics' of Active Matter
- Nonequilibrium equation of state in suspensions of active colloids
- Active colloidal suspensions: Clustering and phase behavior
- Orientational order in concentrated suspensions of spherical microswimmers
- Spontaneous aggregation and global polar ordering in squirmer suspensions
- Defect-Mediated Phase Transitions in Active Soft Matter
- Emergent self-propulsion at low Reynolds number
Cited by in corpus (8)
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- Systematic extension of the Cahn-Hilliard model for motility-induced phase separation
- Statistical mechanics of transport processes in active fluids: Equations of hydrodynamics
- Three-body correlations and conditional forces in suspensions of active hard disks
- Theoretical approaches to the steady-state statistical physics of interacting dissipative units