Dynamics of thermal vibrational motions and stringlike jump motions in three-dimensional glass-forming liquids.
Dynamics of thermal vibrational motions and stringlike jump motions in three-dimensional glass-forming liquids.
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DOI：
10.1063/1.4770337
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发表时间：
2013-01
期刊：
影响因子：
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通讯作者：
T. Kawasaki;A. Onuki
中科院分区：
文献类型：
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作者：
T. Kawasaki;A. Onuki
利用分子动力学方法模拟了三维玻璃形成液体的热振动运动、由弦状跳跃运动引起的构型变化以及它们之间的密切关系。根据为每个粒子i定义的振动长度Si（t）来可视化非均匀振动运动。计算了Si（t）（2）非均匀性的结构因子，结果表明，Si（t）（2）非均匀性具有相当大的长波增强效应。通过考察弦的诞生时间，我们发现它们是集体地、间歇地出现的。我们发现，具有较大的Si（t）的粒子往往触发跳跃运动更频繁地在较晚的时间比那些具有较小的Si（t）。我们还表明，具有较少的键的粒子往往具有较大的Si（t），并更频繁地参与弦状运动。
Using molecular dynamics simulation on a glass-forming liquid in three dimensions, we investigate the thermal vibrational motions, the configuration changes caused by stringlike jump motions, and their close correlations. The heterogeneous vibrational motions are visualized in terms of a vibration length Si(t) defined for each particle i. The structure factor for the inhomogeneity of Si(t)(2) is also calculated, which exhibits considerable long wavelength enhancement. By examining the birth times of strings, they are shown to appear collectively and intermittently. We show that particles with larger Si(t) tend to trigger jump motions more frequently at later times than those with smaller Si(t). We also show that the particles with fewer bonds tend to have larger Si(t) and participate more frequently in the stringlike motions.