Menzel A M
Institut für Theoretische Physik II: Weiche Materie, Heinrich-Heine-Universität Düsseldorf, Universitätsstraße 1, D-40225 Düsseldorf, Germany.
J Phys Condens Matter. 2013 Dec 18;25(50):505103. doi: 10.1088/0953-8984/25/50/505103. Epub 2013 Nov 25.
One standard approach to describe the collective behaviour of self-propelled particles is the Vicsek model: point-like self-propelled particles tend to align their migration directions to the ones of their nearer neighbours at each time-step. Here we use a variant of the Vicsek model that includes pairwise repulsive interactions. Confining the system between parallel walls can qualitatively change its appearance: a laning state can emerge that is different from the ones previously reported. All lanes show on average the same migration direction of the contained particles with a finite separation distance between the lanes. Furthermore, in certain parameter ranges we observe collectively migrating clusters that arrange in an approximately hexagonal way. We suggest that the mechanism behind these regular textures is an overreaction in the alignment mechanism. Considering the more realistic scenario of non-point-like particles in the presence of confining surfaces is generally important for the comparison to experimental systems.
点状自驱动粒子在每个时间步倾向于将其迁移方向与更近邻粒子的方向对齐。在这里，我们使用了维克塞克模型的一个变体，该变体包括成对排斥相互作用。将系统限制在平行壁之间会定性地改变其外观：可能会出现一种与先前报道的不同的车道状态。所有车道平均显示所含粒子的相同迁移方向，且车道之间有有限的间隔距离。此外，在某些参数范围内，我们观察到以近似六边形方式排列的集体迁移簇。我们认为这些规则纹理背后的机制是对齐机制中的过度反应。考虑存在限制表面时非点状粒子这种更现实的情况，对于与实验系统进行比较通常很重要。
