论文标题
密集活动系统中相位行为的动态路径依赖性
Dynamic path dependence of phase behaviors in dense active system
论文作者
论文摘要
在非平衡活动系统中存在丰富的新兴相位行为。羊群和聚类是两个代表性的动态阶段。这两个阶段之间的关系尚不清楚。在论文中，我们从数值上研究了由具有主动重新定位的自propelled颗粒组成的系统中植入和聚类的演变。我们考虑不同初始状态下的羊群和聚类阶段之间的相互作用，并观察一个不稳定的域，即使在没有显式吸引力的情况下，由于初始状态，因此在顺序的参数相图中观察了域。这一点与以前的发现不同，即主动角波动导致集体运动的较早崩溃以及对齐的活性粒子中新的双稳定状态的出现[R.Grossmann等，New J. Phys.073033,14（2012）]。特别是，我们发现双稳定状态的存在是由于不同初始状态引起的动态路径的多样性所致。通过增加（降低）初始排序程度，可以将双稳定状态转移到有序的羊群（无序聚类）状态。这些结果启发了我们为操纵活跃系统的新兴行为和集体运动铺平了道路。
There are rich emergent phase behaviors in non-equilibrium active systems. Flocking and clustering are two representative dynamic phases. The relationship between these two phases is still unclear. In the paper, we numerically investigate the evolution of flocking and clustering in a system consisting of self-propelled particles with active reorientation. We consider the interplay between flocking and clustering phases under different initial states, and observe an unstable domain in order parameters phase diagrams due to initial states even in the absence of an explicit attraction. This point is different from the previous finding that active angular fluctuations lead to an earlier breakdown of collective motion and the emergence of a new bi-stable regime in the aligned active particles [R.Grossmann et al, New J. Phys.073033,14 (2012)]. In particular, we find that the existence of bi-stable states is due to the diversity of dynamic paths arising from different initial states. By increasing (decreasing) the initial degree of ordering, the bi-stable state can be shifted to a more ordered flocking (disordered clustering) state. These results enlighten us pave the way to manipulate emergent behaviors and collective motions of active system.
