Direct Evaluation of Rare Events in Active Matter from Variational Path Sampling
Direct Evaluation of Rare Events in Active Matter from Variational Path Sampling
复制标题
通过变分路径采样直接评估活性物质中的稀有事件
DOI：
10.1103/physrevlett.128.028005
复制
发表时间：
2022
影响因子：
8.6
通讯作者：
Limmer, David T.
中科院分区：
文献类型：
--
作者：
Das, Avishek;Kuznets-Speck, Benjamin;Limmer, David T.
活性物质代表了一大类系统，由于能量的局部注入而远离平衡状态。与它们的被动类似物一样，主动物质中不同亚稳态之间的转变是通过罕见的波动进行的。然而，它们详细的平衡破坏动态使得这些事件难以研究。在这里，我们提出了一种模拟方法，用于评估一般非平衡系统中罕见事件的发生率和机制，并将其应用于研究活性流体中被动溶质的构象变化。该方法采用控制力的变分优化，使罕见事件成为典型事件，并以路径分区函数的比率形式提供其速率的精确估计。使用这种方法，我们发现增加活性浴中的活性可以提高被动溶质的构象转换速率，其方式与随机热力学的最新界限一致。
Active matter represents a broad class of systems that evolve far from equilibrium due to the local injection of energy. Like their passive analogs, transformations between distinct metastable states in active matter proceed through rare fluctuations; however, their detailed balance violating dynamics renders these events difficult to study. Here, we present a simulation method for evaluating the rate and mechanism of rare events in generic nonequilibrium systems and apply it to study the conformational changes of a passive solute in an active fluid. The method employs a variational optimization of a control force that renders the rare event a typical one, supplying an exact estimate of its rate as a ratio of path partition functions. Using this method we find that increasing activity in the active bath can enhance the rate of conformational switching of the passive solute in a manner consistent with recent bounds from stochastic thermodynamics.