Active matter: Quantifying the departure from equilibrium
Active matter: Quantifying the departure from equilibrium
复制标题
活性物质：量化偏离平衡的情况
DOI：
10.1103/physreve.102.022607
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发表时间：
2020
影响因子：
2.4
通讯作者：
Szamel, Grzegorz
中科院分区：
文献类型：
--
作者：
Flenner, Elijah;Szamel, Grzegorz
活性物质系统在单个组分的水平上被驱离平衡。一个被广泛研究的类别是在粒子间相互作用和自推进的综合影响下移动的非热粒子系统，后者根据Ornstein-Uhlenbeck随机过程演化。直觉上，这些所谓的主动奥恩斯坦-乌伦贝克粒子（AOUP）系统在更长的自推进持续时间内远离平衡。定量地，这是证实了增加的等时速度相关性（这是微不足道的平衡），并增加违反爱因斯坦之间的自扩散和迁移率系数的关系。相反，熵产生率，从位置空间轨迹和其时间反演对应的概率的比率计算，具有非单调依赖于持续时间。因此，它没有正确地量化AOUP系统从平衡的偏离。
Active matter systems are driven out of equilibrium at the level of individual constituents. One widely studied class are systems of athermal particles that move under the combined influence of interparticle interactions and self-propulsions, with the latter evolving according to the Ornstein-Uhlenbeck stochastic process. Intuitively, these so-called active Ornstein-Uhlenbeck particle (AOUP) systems are farther from equilibrium for longer self-propulsion persistence times. Quantitatively, this is confirmed by the increasing equal-time velocity correlations (which are trivial in equilibrium) and by the increasing violation of the Einstein relation between the self-diffusion and mobility coefficients. In contrast, the entropy production rate, calculated from the ratio of the probabilities of the position space trajectory and its time-reversed counterpart, has a nonmonotonic dependence on the persistence time. Thus, it does not properly quantify the departure of AOUP systems from equilibrium.