Relaxation in a Phase-separating Two-dimensional Active Matter System with Alignment Interaction

Abstract

Via computer simulations we study kinetics of pattern formation in a two-dimensional active matter system. Self-propulsion in our model is incorporated via the Vicsek-like activity, i.e., particles have the tendency of aligning their velocities with the average directions of motion of their neighbors. In addition to this dynamic or active interaction, there exists passive inter-particle interaction in the model for which we have chosen the standard Lennard-Jones form. Following quenches of homogeneous configurations to a point deep inside the region of coexistence between high and low density phases, as the systems exhibit formation and evolution of particle-rich clusters, we investigate properties related to the morphology, growth and aging. A focus of our study is on the understanding of the effects of structure on growth and aging. To quantify the latter we use the two-time order-parameter autocorrelation function. This correlation, as well as the growth, is observed to follow power-law time dependence, qualitatively similar to the scaling behavior reported for passive systems. The values of the exponents have been estimated and discussed by comparing with the previously obtained numbers for other dimensions as well as with the new results for the passive limit of the considered model. We have also presented results on the effects of temperature on the activity mediated phase separation.

10 pages, 10 figures

References in corpus (15)

• Novel type of phase transition in a system of self-driven particles
• Self-motile colloidal particles: from directed propulsion to random walk
• Interaction Ruling Animal Collective Behaviour Depends on Topological rather than Metric Distance: Evidence from a Field Study
• Motility-Induced Phase Separation
• Physics of Microswimmers - Single Particle Motion and Collective Behavior
• Hierarchical group dynamics in pigeon flocks
• Statistical Mechanics of Interacting Run-and-Tumble Bacteria
• Active phase separation in mixtures of chemically interacting particles
• Critical Dynamics in a Binary Fluid: Simulations and Finite-size Scaling
• Influence of thermal fluctuations on the geometry of the interfaces of the quenched Ising model
• Estimation of the critical behavior in an active colloidal system with Vicsek-like interactions
• Reaction processes among self-propelled particles
• Droplet growth during vapor-liquid transition in a 2D Lennard-Jones fluid
• Aging Phenomena during Phase Separation in Fluids: Decay of autocorrelation for vapor-liquid transitions
• Hydrodynamic correlations of viscoelastic fluids by multiparticle collision dynamics simulations