静态障碍物存在下智能活性布朗粒子的集体行为
Collective Behavior of Intelligent Active Brownian Particles in the Presence of a Static Obstacle
- Indian Institute of Technology Bhubaneswar（印度技术学院布巴内斯瓦尔分校）
- University of Greifswald（格赖夫斯瓦尔德大学）
机构由 AI 辅助整理，请以论文原文为准。
中文总结 AI 辅助
本研究通过模拟发现，基于视觉感知的智能活性布朗粒子在静态障碍物下，其边界聚集随活性增加而减少，且扩散系数非单调变化，驻留时间大幅缩短，可用于复杂环境中的粒子控制。
中文摘要 AI 辅助
利用计算机模拟，我们研究了二维活性布朗粒子（ABPs）在体相以及存在单个静态圆形障碍物情况下，具有排除体积相互作用的集体行为。通过基于视觉的转向机制引入感知介导的相互作用，该机制使每个粒子能够根据预定视觉锥内邻近粒子的瞬时位置重新调整其推进方向。在体相中，这些智能活性布朗粒子（iABPs）表现出不同的集体状态，包括聚集团簇、蠕虫状链、蠕虫-团簇共存态和稀薄气体相。我们使用形状各向异性参数表征这些状态，并构建了相应的相图。静态障碍物的存在（其与粒子通过纯排斥力相互作用）定性地改变了它们的集体行为。与常规ABPs（其围绕障碍物的各向同性聚集随活性增加而增加）相比，iABPs表现出相反的趋势，即边界聚集随活性增加而减少。我们进一步确定了描述障碍物边界处粒子聚集和团簇形成的经验标度关系。因此，iABPs的相对有效扩散系数对自推进速度表现出非单调依赖，而常规ABPs的相对有效扩散系数则随活性增加单调下降。此外，我们表明iABPs的驻留时间比常规ABPs短几个数量级，这表明感知介导的相互作用可用于控制复杂环境中活性粒子的组织和输运。
英文摘要
Using computer simulations, we investigate the collective behavior of two-dimensional active Brownian particles (ABPs) with excluded-volume interactions in the bulk and in the presence of a single static circular obstacle. Perception-mediated interactions are introduced through a vision-based steering mechanism that enables each particle to reorient its propulsion direction according to the instantaneous positions of neighboring particles within a prescribed vision cone. In the bulk, these intelligent active Brownian particles (iABPs) exhibit distinct collective states, including aggregated clusters, worm-like chains, worm-aggregate coexistence, and dilute gas phases. We characterize these states using a shape anisotropy parameter and construct the corresponding phase diagrams. The presence of a static obstacle, which interacts with the particles through purely repulsive forces, qualitatively alters their collective behavior. In contrast to conventional ABPs, whose isotropic accumulation around the obstacle increases with activity, iABPs exhibit the opposite trend, with boundary accumulation decreasing as the activity increases. We further identify empirical scaling relations that describe particle accumulation and cluster formation at the obstacle boundary. Consequently, the relative effective diffusion coefficient of iABPs displays a nonmonotonic dependence on self-propulsion speed, whereas that of conventional ABPs decreases monotonically with increasing activity. In addition, we show that the residence times of iABPs are orders of magnitude shorter than those of conventional ABPs, indicating that perception-mediated interactions can be useful for controlling the organization and transport of active particles in complex environments.
