Maitra Ananyo, Voituriez Raphael
Sorbonne Université and CNRS, Laboratoire Jean Perrin, F-75005 Paris, France.
Sorbonne Université and CNRS, Laboratoire de Physique Théorique de la Matière Condensée, F-75005 Paris, France.
Phys Rev Lett. 2020 Jan 31;124(4):048003. doi: 10.1103/PhysRevLett.124.048003.
Can a bath of isotropic but active particles promote ordering of anisotropic but passive particles? In this Letter, we uncover a fluctuation-driven mechanism by which this is possible. Somewhat counterintuitively, we show that the passive particles tend to be more ordered upon increasing the noise strength of the active isotropic bath. We first demonstrate this in a general dynamical model for a nonconserved order parameter (model A) coupled to an active isotropic field and then concentrate on two examples: (i) a collection of polar rods on a substrate in an active isotropic bath and (ii) a passive apolar suspension in a momentum conserved, actively forced but isotropic fluid, which are relevant for current research in active systems. Our theory, which is relevant for understanding ordering transitions in out-of-equilibrium systems can be tested in experiments, for instance, by introducing a low concentration of passive rodlike objects in active isotropic fluids and, since it is applicable to any nonconserved dynamical field, may have applications far beyond active matter.
各向同性但具有活性的粒子浴能否促进各向异性但无活性的粒子的有序排列？在本快报中，我们揭示了一种波动驱动机制，通过该机制这是可能的。有点违反直觉的是，我们表明，随着活性各向同性浴噪声强度的增加，无活性粒子往往会更加有序。我们首先在一个与活性各向同性场耦合的非守恒序参量的一般动力学模型（模型A）中证明这一点，然后专注于两个例子：（i）处于活性各向同性浴中的基底上的一组极性棒，以及（ii）处于动量守恒、有源驱动但各向同性流体中的无活性非极性悬浮液，这两个例子与活性系统的当前研究相关。我们的理论与理解非平衡系统中的有序转变相关，可以在实验中进行检验，例如，通过在活性各向同性流体中引入低浓度的无活性棒状物体，并且由于它适用于任何非守恒动力学场，可能具有远远超出活性物质的应用。
