arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2202.07355cond-mat.soft
收藏

热活性布朗粒子的相干运动

The coherent motions of thermal active Brownian particles

Cheng Yang, Ying Zeng, Shun Xu, Xin Zhou

AI总结:

热噪声掩盖了微观活性布朗粒子(ABP)运动间的相关性,本文通过在多滞后时间下对瞬时速度求平均,发现在比平动特征时间小一个数量级的尺度内,热涨落ABP的运动高度相干且与结构有序性一致。

摘要:

活性物质表现出许多有趣的非平衡特征,例如,没有任何吸引和排列相互作用的活性布朗粒子(ABP)能够发生迁移率诱导的相变,形成兼具结构有序和动力学相干的致密区域。最近,在非热ABP系统中发现了致密且有序团簇内粒子间的速度相关性,然而,如果引入热噪声来描述微观ABP,这种相关性似乎会消失,这给ABP中结构与动力学一致性的一般性带来了一些困惑。在此,我们证明热噪声在ABP的瞬时速度上施加了大的随机项,阻碍了对ABP运动中(微小)相关性的观察。通过在不同滞后时间下对瞬时速度求平均(或等价地计算位移),我们表明,在比平动特征时间小一个数量级的时间尺度内,热涨落ABP的运动在空间上是高度相干的,并且与ABP的结构有序性一致。

英文摘要:

Active matter exhibits many intriguing non-equilibrium character, \emph{e.g.}, the active Brownian particles (ABP) without any attractive and aligned interactions can occur the mobility-induced phase transition to form some dense domains with both the structural ordering and dynamical coherence. Recently, the velocity correlation among the particles in the dense and ordered clusters was found in athermal ABP systems, however, seemed to disappear if including the thermal noises to describe microscopic ABPs, bringing some confusion about the generality of the consistence between structure and dynamics in ABPs. Here we demonstrate that the thermal noises imposing a large random term on the instantaneous velocity of ABPs hinder the observation of the (small) correlation in motions of ABPs. By averaging the instantaneous velocity (or equivalently, calculating the displacement) in various lag times, we show that the motions of thermal-fluctuated ABPs in the one order of magnitude smaller than the translational characteristic time are highly coherent and consistent spatially with the structural ordering of the ABPs.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑