Debiossac Maxime, Rosinberg Martin Luc, Lutz Eric, Kiesel Nikolai
University of Vienna, Faculty of Physics, VCQ, Boltzmanngasse 5, A-1090 Vienna, Austria.
LPTMC, CNRS-UMR 7600, Sorbonne Université, 4 place Jussieu, 75252 Paris Cedex 05, France.
Phys Rev Lett. 2022 May 20;128(20):200601. doi: 10.1103/PhysRevLett.128.200601.
Causality is an important assumption underlying nonequilibrium generalizations of the second law of thermodynamics known as fluctuation relations. We here experimentally study the nonequilibrium statistical properties of the work and of the entropy production for an optically trapped, underdamped nanoparticle continuously subjected to a time-delayed feedback control. Whereas the non-Markovian feedback depends on the past position of the particle for a forward trajectory, it depends on its future position for a time-reversed path, and is therefore acausal. In the steady-state regime, we show that the corresponding fluctuation relations in the long-time limit exhibit a clear signature of this acausality, even though the time-reversed dynamics is not physically realizable.
因果关系是被称为涨落关系的热力学第二定律非平衡推广的一个重要假设。我们在此通过实验研究了一个光学捕获的、欠阻尼纳米粒子在持续受到延时反馈控制时，功和熵产生的非平衡统计特性。非马尔可夫反馈对于正向轨迹取决于粒子的过去位置，而对于时间反演路径则取决于其未来位置，因此是非因果的。在稳态 regime 中，我们表明，即使时间反演动力学在物理上不可实现，长时间极限下相应的涨落关系仍呈现出这种非因果性的明显特征。
