论文标题
被困的活动粒子的稳态轨迹的不可逆转如何？
How irreversible are steady-state trajectories of a trapped active particle?
论文作者
论文摘要
主动粒子的定义特征是它们通过将化学能局部转化为有向运动来不断推动自己。这种主动的自我驱动阻止它们与热环境平衡（例如水溶液），从而使它们永久地脱离平衡。然而，活性颗粒的空间动力学可能具有某些平衡特征，尤其是在稳态中。在这里，我们将重点放在单个空间轨迹的时间反转对称性上，作为独特的平衡特征。我们研究了被困的活动粒子的稳态轨迹在多大程度上遵守或打破这种时间反转对称性。在活跃的Ornstein-Uhlenbeck颗粒的框架内，我们发现谐波电位中的稳态轨迹完全满足路径的时间反转对称性，而这种对称性通常在肛门电位中损坏。
The defining feature of active particles is that they constantly propel themselves by locally converting chemical energy into directed motion. This active self-propulsion prevents them from equilibrating with their thermal environment (e.g., an aqueous solution), thus keeping them permanently out of equilibrium. Nevertheless, the spatial dynamics of active particles might share certain equilibrium features, in particular in the steady state. We here focus on the time-reversal symmetry of individual spatial trajectories as a distinct equilibrium characteristic. We investigate to what extent the steady-state trajectories of a trapped active particle obey or break this time-reversal symmetry. Within the framework of active Ornstein-Uhlenbeck particles we find that the steady-state trajectories in a harmonic potential fulfill path-wise time-reversal symmetry exactly, while this symmetry is typically broken in anharmonic potentials.
