Kinetic Heterogeneities in Highly Supercooled Liquids
Kinetic Heterogeneities in Highly Supercooled Liquids
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高度过冷液体中的动力学非均质性
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
A. Onuki
中科院分区：
文献类型：
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作者：
R. Yamamoto;A. Onuki
本文采用分子动力学方法研究了一种高度过冷的二维流体混合物。我们跟踪粒子对之间的键断裂事件，它发生在α弛豫时间τ α的尺度上。在宽度为0.05τ α量级的时间间隔内断裂的键的空间分布中发现了类似于伊辛体系中临界涨落的大尺度不均匀性。断裂键密度的结构因子很好地近似于Ornstein-Zernike形式。在所研究的最低温度下，相关长度为100 σ 1的数量级，σ 1为粒度。由此确定的弱键合区域随时间演化，具有很强的空间相关性。
We study a highly supercooled two-dimensional fluid mixture via molecular dynamics simulation. We follow bond breakage events among particle pairs, which occur on the scale of the α relaxation time τ α . Large scale heterogeneities analogous to the critical fluctuations in Ising systems are found in the spatial distribution of bonds which are broken in a time interval with a width of order 0.05τ α . The structure factor of the broken bond density is well approximated by the Ornstein-Zernike form. The correlation length is of order 100 σ 1 at the lowest temperature studied, σ 1 being the particle size. The weakly bonded regions thus identified evolve in time with strong spatial correlations.