Understanding topological defects in fluidized dry active nematics
Understanding topological defects in fluidized dry active nematics
复制标题
了解流化干活性向列相的拓扑缺陷
DOI：
10.1039/d1sm01405f
复制
发表时间：
2022
期刊：
影响因子：
3.4
通讯作者：
Gao, Tong
中科院分区：
文献类型：
--
作者：
Palmer, Bryce;Chen, Sheng;Govan, Patrick;Yan, Wen;Gao, Tong
自推进棒（SPR）的密集组合体可能表现出迷人的集体行为和远离平衡的异常物理性质。使用大规模布朗动力学模拟，我们研究了致密干SPR（即，没有流体动力学效应），其形成令人联想到近晶序的显著局部位置拓扑结构。我们发现近晶类棒层的变形可以产生独特的极性结构，导致±1/2阶缺陷的缓慢平移和旋转，这与在湿活性物质中观察到的快速流动缺陷运动有根本不同。我们测量和表征拓扑缺陷的统计特性，并揭示它们与相干结构的联系。此外，我们构建了一个自下而上的有源液晶模型来分析极道的不稳定性，这有效地导致了互锁的极道之间的缺陷形成，并作为大规模群集运动的起源。
Dense assemblies of self-propelling rods (SPRs) may exhibit fascinating collective behaviors and anomalous physical properties that are far away from equilibrium. Using large-scale Brownian dynamics simulations, we investigate the dynamics of disclination defects in 2D fluidized swarming motions of dense dry SPRs (i.e., without hydrodynamic effects) that form notable local positional topological structures that are reminiscent of smectic order. We find the deformations of smectic-like rod layers can create unique polar structures that lead to slow translations and rotations of ±1/2-order defects, which are fundamentally different from the fast streaming defect motions observed in wet active matter. We measure and characterize the statistical properties of topological defects and reveal their connections with the coherent structures. Furthermore, we construct a bottom-up active-liquid-crystal model to analyze the instability of polar lanes, which effectively leads to defect formation between interlocked polar lanes and serves as the origin of the large-scale swarming motions.