Caprini Lorenzo, Hernández-García Emilio, López Cristóbal, Marini Bettolo Marconi Umberto
Gran Sasso Science Institute (GSSI), Via. F. Crispi 7, 67100, L'Aquila, Italy.
IFISC (CSIC-UIB), Instituto de Física Interdisciplinar y Sistemas Complejos, Campus Universitat de les Illes Balears, E-07122, Palma de Mallorca, Spain.
Sci Rep. 2019 Nov 13;9(1):16687. doi: 10.1038/s41598-019-52420-1.
We study a system of active particles with soft repulsive interactions that lead to an active cluster-crystal phase in two dimensions. We use two different modelizations of the active force - Active Brownian particles (ABP) and Ornstein-Uhlenbeck particles (AOUP) - and focus on analogies and differences between them. We study the different phases appearing in the system, in particular, the formation of ordered patterns drifting in space without being altered. We develop an effective description which captures some properties of the stable clusters for both ABP and AOUP. As an additional point, we confine such a system in a large channel, in order to study the interplay between the cluster crystal phase and the well-known accumulation near the walls, a phenomenology typical of active particles. For small activities, we find clusters attached to the walls and deformed, while for large values of the active force they collapse in stripes parallel to the walls.
我们研究了一个具有软排斥相互作用的活性粒子系统，该系统在二维空间中会导致活性团簇-晶体相。我们使用了两种不同的活性力模型——活性布朗粒子（ABP）和奥恩斯坦-乌伦贝克粒子（AOUP）——并关注它们之间的异同。我们研究了系统中出现的不同相，特别是在空间中漂移且不发生改变的有序图案的形成。我们开发了一种有效描述，它捕捉了ABP和AOUP两种情况下稳定团簇的一些特性。另外，我们将这样一个系统限制在一个大通道中，以研究团簇晶体相和壁附近众所周知的积累现象之间的相互作用，这是活性粒子的一种典型现象学。对于小活性，我们发现团簇附着在壁上并发生变形，而对于大活性力值，它们会坍缩成与壁平行的条纹。
