Brownian yet non-Gaussian diffusion of a light particle in heavy gas: Lorentz-gas-based analysis.
Brownian yet non-Gaussian diffusion of a light particle in heavy gas: Lorentz-gas-based analysis.
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重气体中轻粒子的布朗非高斯扩散：基于洛伦兹气体的分析。
DOI：
10.1103/physreve.108.044129
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Takashi Uneyama
中科院分区：
文献类型：
--
作者：
Fumiaki Nakai;Takashi Uneyama
最近在具有质量和分数对比度的气体混合物中观察到非高斯扩散[F。Nakai等人，Phys. Rev. E 107，014605（2023）2470-004510.1103/PhysRevE.107.014605]。质量小的微小气体粒子的均方位移随时间呈线性分布，而位移分布偏离高斯分布，称为布朗非高斯扩散。在这项工作中，我们从理论上分析这种情况下，质量对比度是足够大的。主要的重粒子可以被解释为不动的障碍物，而次要的轻粒子在中间时间尺度内表现得像洛伦兹气体粒子。尽管气体混合物和传统的洛伦兹气体系统之间的相似性，洛伦兹气体描述不能完全描述布朗但非高斯扩散。一个成功的描述可以通过正则系综平均的统计量的洛伦兹气体在初始速度。进一步，我们证明了货车霍韦关联函数具有非指数尾，这与在各种系统中观察到的指数尾相反。
Non-Gaussian diffusion was recently observed in a gas mixture with mass and fraction contrast [F. Nakai et al., Phys. Rev. E 107, 014605 (2023)2470-004510.1103/PhysRevE.107.014605]. The mean-square displacement of a minor gas particle with a small mass is linear in time, while the displacement distribution deviates from the Gaussian distribution, which is called the Brownian yet non-Gaussian diffusion. In this work, we theoretically analyze this case where the mass contrast is sufficiently large. Major heavy particles can be interpreted as immobile obstacles, and a minor light particle behaves like a Lorentz gas particle within an intermediate timescale. Despite the similarity between the gas mixture and the conventional Lorentz gas system, the Lorentz gas description cannot fully describe the Brownian yet non-Gaussian diffusion. A successful description can be achieved through a canonical ensemble average of the statistical quantities of the Lorentz gas over the initial speed. Furhter, we show that the van Hove correlation function has a nonexponential tail, which is contrary to the exponential tail observed in various systems.
活性布朗粒子在随机洛伦兹气体中运动
DOI：
10.1140/epje/i2017-11510-0
发表时间：
2017
期刊：
The European Physical Journal E
影响因子：
--
作者：
M. Zeitz;K. Wolff;H. Stark
通讯作者：
H. Stark