随机静态环境中棒的动力学：大尺度的非高斯性
摘要
We present molecular dynamics simulations of the motion of a single rod in a two-dimensional random static array of disks. For long rods the mean-squared displacement of the center-of-mass shows a cage effect similar to that observed in supercooled liquids or dense colloidal systems. We have determined the time-dependence of the non-Gaussian parameter for different rod lengths. It is found that the long-time regime is strongly non-Gaussian even at length scales of the order of 10-15 times the rod length, thus showing the heterogeneity of the dynamics at such length scales. 我们进行了在二维随机静态硬盘数组中的单根棒运动的分子动力学模拟。对于长棒而言, 中心质量的均方位移显示出类似于超冷液体或稠密胶体系统中观察到的笼效应。我们确定了不同棒长度下非高斯参数随时间的变化规律。发现即使在棒长长度的 10-15 倍尺度上, 长时间尺度的运动仍然呈现强烈的非高斯性, 从而表明这些尺度上的运动动力学具有显著的各向异性。
引用
@article{arxiv.cond-mat/0303510,
title = {Dynamics of a rod in a random static environment: non-Gaussianity at large length scales},
author = {A. J. Moreno and W. Kob},
journal= {arXiv preprint arXiv:cond-mat/0303510},
year = {2007}
}
备注
7 pages, 3 figures. Submitted to Philosophical Magazine B. Proceedings of the 9th International Workshop on Disordered Systems, 10-13 March 2003, Molveno-Trento (Italy)