SUPA, School of Physics and Astronomy, University of Edinburgh, JCMB Kings Buildings, Edinburgh EH9 3JZ, United Kingdom.
Phys Rev Lett. 2013 Oct 4;111(14):145702. doi: 10.1103/PhysRevLett.111.145702. Epub 2013 Oct 2.
Active Brownian particles (ABPs), when subject to purely repulsive interactions, are known to undergo activity-induced phase separation broadly resembling an equilibrium (attraction-induced) gas-liquid coexistence. Here we present an accurate continuum theory for the dynamics of phase-separating ABPs, derived by direct coarse graining, capturing leading-order density gradient terms alongside an effective bulk free energy. Such gradient terms do not obey detailed balance; yet we find coarsening dynamics closely resembling that of equilibrium phase separation. Our continuum theory is numerically compared to large-scale direct simulations of ABPs and accurately accounts for domain growth kinetics, domain topologies, and coexistence densities.
活性布朗粒子（ABP）在受到纯粹排斥相互作用时，已知会经历类似于平衡（吸引诱导）气液共存的活性诱导相分离。在这里，我们通过直接粗粒化提出了一个用于相分离 ABP 动力学的精确连续体理论，该理论捕捉到了主导阶密度梯度项以及有效的体自由能。这些梯度项不遵守详细平衡；然而，我们发现粗粒化动力学非常类似于平衡相分离。我们的连续体理论与 ABP 的大规模直接模拟进行了数值比较，并准确地解释了域生长动力学、域拓扑和共存密度。
