Superadiabatic demixing in nonequilibrium colloids
Superadiabatic demixing in nonequilibrium colloids
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DOI：
10.1038/s42005-020-0287-5
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发表时间：
2020-01-24
影响因子：
5.5
通讯作者：
Schmidt, Matthias
中科院分区：
文献类型：
--
作者：
Geigenfeind, Thomas;de las Heras, Daniel;Schmidt, Matthias
分散的胶体颗粒，设置成系统的运动由一个受控的外部领域构成了极好的模型系统，用于研究远离平衡的结构形成。在这里，我们确定了一个独特的分层力，所产生的排斥粒子间的相互作用驱动的二元胶体。相应的分层力密度在空间和时间上被解析，并且它抵消了由于局部混合熵的梯度而产生的扩散流。我们构造了一个幂函数近似的过阻尼布朗动力学，描述了作为一个拮抗剂的绝热混合起源于自由能的超绝热分离。我们将这一理论应用于胶体泳道的形成。对绝热力、结构力、阻力和粘性力的计算结果与布朗动力学计算机模拟结果吻合得很好。超绝热去混合可以解释系统中混合态、窄化态和堵塞态的出现，寻找驱动粒子系统中的去混合机制是非平衡统计物理学基础建设中的一个具有挑战性的课题。在这项工作中，作者提出了一个理论框架的基础上，功率泛函近似，描述超绝热分层模拟驱动的胶体粒子系统。
Dispersed colloidal particles that are set into systematic motion by a controlled external field constitute excellent model systems for studying structure formation far from equilibrium. Here we identify a unique demixing force that arises from repulsive interparticle interactions in driven binary colloids. The corresponding demixing force density is resolved in space and in time and it counteracts diffusive currents which arise due to gradients of the local mixing entropy. We construct a power functional approximation for overdamped Brownian dynamics that describes superadiabatic demixing as an antagonist to adiabatic mixing as originates from the free energy. We apply the theory to colloidal lane formation. The theoretical results are in excellent agreement with our Brownian dynamics computer simulation results for adiabatic, structural, drag and viscous forces. Superadiabatic demixing allows to rationalize the emergence of mixed, laned and jammed states in the system.The search for demixing mechanisms in driven particle systems is a challenging topic in the fundamental construction of non-equilibrium statistical physics. In this work the authors propose a theoretical framework based on a power functional approximation that describes superadiabatic demixing in simulations of driven colloidal particle systems.