Jayaram Ashreya, Fischer Andreas, Speck Thomas
Institut für Physik, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany.
Phys Rev E. 2020 Feb;101(2-1):022602. doi: 10.1103/PhysRevE.101.022602.
We study numerically the phase behavior of self-propelled elliptical particles interacting through the "hard" repulsive Gay-Berne potential at infinite Péclet number. Changing a single parameter, the aspect ratio, allows us to continuously go from discoid active Brownian particles to elongated polar rods. Discoids show phase separation, which changes to a cluster state of polar domains, which then form polar bands as the aspect ratio is increased. From the simulations, we identify and extract the two effective parameters entering the mean-field description: the force imbalance coefficient and the effective coupling to the local polarization. These two coefficients are sufficient to obtain a complete and consistent picture, unifying the paradigms of scalar and polar active matter.
我们对通过“硬”排斥性盖伊 - 伯尔尼势相互作用的自推进椭圆粒子在无限皮克莱数下的相行为进行了数值研究。改变单个参数——纵横比，使我们能够连续地从盘状活性布朗粒子转变为细长的极性棒。盘状粒子表现出相分离，随着纵横比增加，相分离转变为极性域的簇状态，进而形成极性带。通过模拟，我们识别并提取了进入平均场描述的两个有效参数：力不平衡系数和与局部极化的有效耦合。这两个系数足以获得一个完整且一致的图景，统一标量和极性活性物质的范式。
