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arXiv 2302.02775cond-mat.stat-mech
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非平衡混合物动力学:迁移率模型及其后果

Nonequilibrium mixture dynamics: A model for mobilities and its consequences

Maryam Akaberian, Filipe C Thewes, Peter Sollich, Matthias Krüger

AI总结:

该研究扩展模型B,推导出混合物迁移率矩阵的近似表达式,识别两种迁移率状态,并通过热淬火动力学验证,解析结果与蒙特卡罗模拟吻合,揭示瞬态分级现象。

摘要:

我们扩展了著名的用于液体混合物时间演化的模型B,推导出耦合不同混合物组分的迁移率矩阵的近似表达式。该方法基于一种单组分流体,其中粒子被人为地分组为以“颜色”标记的不同种类。由此产生的迁移率矩阵依赖于一个单一的无量纲参数,该参数可以有效地从实验数据或数值模拟中确定,并将现有的标准形式作为特例包含在内。我们识别出两种不同的迁移率状态,分别对应于集体运动和相互扩散,并展示了它们如何从流体的微观性质中涌现。作为测试场景,我们研究了热淬火后的动力学,从高斯理论中提供了许多一般关系和解析见解。具体来说,对于具有两个或三个组分的系统,等时相关函数的时间演化的解析结果与晶格气体的蒙特卡罗模拟结果吻合良好。观察到丰富的行为,包括瞬态分级的可能性。

英文摘要:

Extending the famous Model B for the time evolution of a liquid mixture, we derive an approximate expression for the mobility matrix that couples the different mixture components. This approach is based on a single component fluid with particles that are artificially grouped into separate species labelled by ``colors''. The resulting mobility matrix depends on a single dimensionless parameter, which can be determined efficiently from experimental data or numerical simulations, and includes existing standard forms as special cases. We identify two distinct mobility regimes, corresponding to collective motion and interdiffusion, respectively, and show how they emerge from the microscopic properties of the fluid. As a test scenario, we study the dynamics after a thermal quench, providing a number of general relations and analytical insights from a Gaussian theory. Specifically, for systems with two or three components, analytical results for the time evolution of the equal time correlation function compare well to results of Monte Carlo simulations of a lattice gas. A rich behavior is observed, including the possibility of transient fractionation.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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