Phase separation and multibody effects in three-dimensional active Brownian particles

Abstract

Simulation studies of the phase diagram of repulsive active Brownian particles in three dimensions reveal that the region of motility-induced phase separation between a high and low density phase is enclosed by a region of gas-crystal phase separation. Near-critical loci and structural crossovers can additionally be identified in analogy with simple fluids. Motivated by the striking similarity to the behaviour of equilibrium fluids with short-ranged pair-wise attractions, we show that a direct mapping to pair potentials in the dilute limit implies interactions that are insufficiently attractive to engender phase separation. Instead, this is driven by the emergence of multi-body effects associated with particle caging that occurs at sufficiently high number density. We quantify these effects via information-theoretical measures of $n$-body effective interactions extracted from the configurational structure.

References in corpus (7)

• Motility-Induced Phase Separation
• Beware of density dependent pair potentials
• Effective Interactions in Active Brownian Suspensions
• The vanishing limit of the square-well fluid: the adhesive hard sphere model as a reference system
• Applicability of Effective Pair Potentials for Active Brownian Particles
• On the decay of the pair correlation function and the line of vanishing excess isothermal compressibility in simple fluids
• Three-body interactions in complex fluids: virial coefficients from simulation finite-size effects

Cited by in corpus (1)

• Phase separation of active Brownian particles in two dimensions: Anything for a quiet life