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arXiv 2409.04293cond-mat.stat-mechcond-mat.dis-nncond-mat.soft
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受限晶格洛伦兹气体中的时间依赖动力学

Time-dependent dynamics in the confined lattice Lorentz gas

Institut für Theoretische Physik, Universität Innsbruck(因斯布鲁克大学理论物理研究所);Complex Systems and Statistical Mechanics, Department of Physics and Materials Science, University of Luxembourg(卢森堡大学物理与材料科学系复杂系统与统计力学);Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma(罗马智慧大学机械与航空航天工程系);Laboratory of Molecular Simulation (LSMO), Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL)(洛桑联邦理工学院化学科学与工程研究所分子模拟实验室);Sorbonne Université, CNRS, Laboratoire PHENIX (Physico-Chimie des Electrolytes et Nanosystèmes Interfaciaux)(索邦大学CNRS界面电解质和纳米系统物理化学实验室);Laboratoire de Physique Théorique de la Matière Condensée, CNRS/UPMC(CNRS/巴黎第六大学凝聚态物质理论物理实验室)

A. Squarcini, A. Tinti, P. Illien, O. Bénichou, T. Franosch

AI总结:

研究受限晶格洛伦兹气体中时间依赖动力学,分析驱动力与约束对扩散系数的影响,揭示约束对非解析行为的改变及超扩散现象的持续性。

摘要:

我们研究了一个晶格模型,该模型描述了通过随机放置的障碍物介质中拉动物质点时出现的非平衡动力学。该模型在受限几何中考虑,这与研究约束诱导效应相关。我们通过精确推导出的特征函数,得到适用于障碍物密度一阶的动量矩特性。通过计算速度自相关函数及其长时间尾部,我们发现即使在平衡状态下,系统也表现出维度交叉。这一图景进一步通过漂移速度向非平衡稳态终值的接近得到证实。在长时间内,扩散系数受驱动力和约束的影响,我们对其进行了定量分析。力诱导的扩散系数对约束的存在敏感。后者能够改变无界模型中观察到的力的非解析行为。然后,我们检查了沿驱动力物质点的波动。我们表明,在中间范围内,即使在存在约束的情况下,超扩散的异常行为仍然持续。随机模拟用于测试分析结果的有效性,这些结果精确到障碍物密度的一阶,适用于任意力和约束。

英文摘要:

We study a lattice model describing the non-equilibrium dynamics emerging from the pulling of a tracer particle through a disordered medium occupied by randomly placed obstacles. The model is considered in a restricted geometry pertinent for the investigation of confinement-induced effects. We analytically derive exact results for the characteristic function of the moments valid to first order in the obstacle density. By calculating the velocity autocorrelation function and its long-time tail we find that already in equilibrium the system exhibits a dimensional crossover. This picture is further confirmed by the approach of the drift velocity to its terminal value attained in the non-equilibrium stationary state. At large times the diffusion coefficient is affected by both the driving and confinement in a way that we quantify analytically. The force-induced diffusion coefficient depends sensitively on the presence of confinement. The latter is able to modify qualitatively the non-analytic behavior in the force observed for the unbounded model. We then examine the fluctuations of the tracer particle along the driving force. We show that in the intermediate regime superdiffusive anomalous behavior persists even in the presence of confinement. Stochastic simulations are employed in order to test the validity of the analytic results, exact to first order in the obstacle density and valid for arbitrary force and confinement.

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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