Fodor Étienne, Nardini Cesare, Cates Michael E, Tailleur Julien, Visco Paolo, van Wijland Frédéric
Université Paris Diderot, Sorbonne Paris Cité, MSC, UMR 7057 CNRS, 75205 Paris, France.
SUPA, School of Physics and Astronomy, University of Edinburgh, Edinburgh EH9 3FD, United Kingdom.
Phys Rev Lett. 2016 Jul 15;117(3):038103. doi: 10.1103/PhysRevLett.117.038103. Epub 2016 Jul 13.
Active matter systems are driven out of thermal equilibrium by a lack of generalized Stokes-Einstein relation between injection and dissipation of energy at the microscopic scale. We consider such a system of interacting particles, propelled by persistent noises, and show that, at small but finite persistence time, their dynamics still satisfy a time-reversal symmetry. To do so, we compute perturbatively their steady-state measure and show that, for short persistent times, the entropy production rate vanishes. This endows such systems with an effective fluctuation-dissipation theorem akin to that of thermal equilibrium systems. Last, we show how interacting particle systems with viscous drags and correlated noises can be seen as in equilibrium with a viscoelastic bath but driven out of equilibrium by nonconservative forces, hence providing energetic insight into the departure of active systems from equilibrium.
活性物质系统由于微观尺度上能量注入与耗散之间缺乏广义的斯托克斯 - 爱因斯坦关系而偏离热平衡。我们考虑这样一个由持续噪声驱动的相互作用粒子系统，并表明，在小但有限的持续时间下，它们的动力学仍然满足时间反演对称性。为此，我们微扰地计算它们的稳态测度，并表明，对于短持续时间，熵产生率为零。这赋予此类系统一个类似于热平衡系统的有效涨落耗散定理。最后，我们展示了具有粘性阻力和关联噪声的相互作用粒子系统如何可被视为与粘弹性浴处于平衡，但被非保守力驱离平衡，从而为活性系统偏离平衡提供了能量方面的见解。
