论文标题
隐藏的速度排序在密集的自行磁盘的密集悬浮液中
Hidden velocity ordering in dense suspensions of self-propelled disks
论文作者
论文摘要
对球形，纯粹的纯粹活性颗粒的相图的最新研究确定了从液体样到固体样相的过渡，类似于在热平衡处胶体系统中观察到的相似，特别是在二维中，观察到了中间的乙克西相。在这里，我们提供的证据表明，活性致密相（固体，示象和液体）表现出有趣的动力异常。首先，我们揭示了有序域的生长 - 密度和活性，其中颗粒的速度在平行或涡旋状斑块中对齐。其次，当活性很强时，动能的空间分布变得异质，高能区域与晶体结构的缺陷相关。这种空间异质性伴随着时间间歇性，在动能的时间序列中突然达到峰值。观察到的动力异常不存在在密集的平衡系统中，不能仅考虑系统的结构特性来检测到。
Recent studies of the phase diagram for spherical, purely repulsive, active particles established the existence of a transition from a liquid-like to a solid-like phase analogous to the one observed in colloidal systems at thermal equilibrium, in particular in two dimensions an intermediate hexatic phase is observed. Here, we present evidence that the active dense phases (solid, hexatic and liquid) exhibit interesting dynamical anomalies. First, we unveil the growth - with density and activity - of ordered domains where the particles' velocities align in parallel or vortex-like patches. Second, when activity is strong, the spatial distribution of kinetic energy becomes heterogeneous with high energy regions correlated to defects of the crystalline structure. This spatial heterogeneity is accompanied by temporal intermittency, with sudden peaks in the time-series of kinetic energy. The observed dynamical anomalies are not present in a dense equilibrium system and cannot be detected by considering only the structural properties of the system.
