Re-entrant percolation in active Brownian hard disks
arXiv:2409.04141 · doi:10.1039/D4SM00975D
Abstract
Non-equilibrium clustering and percolation are investigated in an archetypal model of two-dimensional active matter using dynamic simulations of self-propelled Brownian repulsive particles. We concentrate on the single-phase region up to moderate levels of activity, before motility-induced phase separation (MIPS) sets in. Weak activity promotes cluster formation and lowers the percolation threshold. However, driving the system further out of equilibrium partly reverses this effect, resulting in a minimum in the critical density for the formation of system-spanning clusters and introducing re-entrant percolation as a function of activity in the pre-MIPS regime. This non-monotonic behaviour arises from competition between activity-induced effective attraction (which eventually leads to MIPS) and activity-driven cluster breakup. Using an adapted iterative Boltzmann inversion method, we derive effective potentials to map weakly active cases onto a passive (equilibrium) model with conservative attraction, which can be characterised by Monte Carlo simulations. While the active and passive systems have practically identical radial distribution functions, we find decisive differences in higher-order structural correlations, to which the percolation threshold is highly sensitive. For sufficiently strong activity, no passive pairwise potential can reproduce the radial distribution function of the active system.
References in corpus (25)
- Athermal Phase Separation of Self-Propelled Particles with no Alignment
- Phase behaviour of active Brownian particles: The role of dimensionality
- Collective motion and nonequilibrium cluster formation in colonies of gliding bacteria
- Full phase diagram of active Brownian disks: from melting to motility-induced phase separation
- Effective Interactions in Active Brownian Suspensions
- Running and tumbling with E. coli in polymeric solutions
- Cooperative Motion of Active Brownian Spheres in Three-Dimensional Dense Suspensions
- Reentrant Phase Behavior in Active Colloids with Attraction
- Competition of percolation and phase separation in a fluid of adhesive hard spheres
- Clustering and heterogeneous dynamics in a kinetic Monte-Carlo model of self-propelled hard disks
- Percolation in suspensions of hard nanoparticles: From spheres to needles
- Applicability of Effective Pair Potentials for Active Brownian Particles
- Clustering and phase behaviour of attractive active particles with hydrodynamics
- Sedimentation of self-propelled Janus colloids: polarization and pressure
- Phase behaviour and dynamical features of a two-dimensional binary mixture of active/passive spherical particles
- Characterization of MIPS in a suspension of repulsive Active Brownian Particles through dynamical features
- Model-free measurement of the pair potential in colloidal fluids using optical microscopy
- Continuum Percolation of Polydisperse Rods in Quadrupole Fields: Theory and Simulations
- Tunneling conductivity in composites of attractive colloids
- Discovering dynamic laws from observations: the case of self-propelled, interacting colloids
- Percolation transition in phase separating active fluid
- Phase behaviour and dynamics of three-dimensional active dumbbell systems
- Dynamical anomalies and structural features of Active Brownian Particles characterised by two repulsive length scales
- Shape, connectedness percolation and electrical conductivity of clusters in suspensions of hard platelets
- An equation of state for active matter