The existence of heterogeneity in the dynamics of supercooled liquids is believed to be one of the hallmarks of the glass transition. Intense research has been carried out in the past to understand the origin of this heterogeneity in dynamics and a possible length scale associated with it. We have done extensive molecular dynamics simulations of a few model glass-forming liquids in three dimensions to understand the temporal evolution of the dynamic heterogeneity and the heterogeneity length scale. We find that although the strength of the dynamic heterogeneity is maximum at a timescale close to the characteristic $\alpha$-relaxation time of the system, dynamic heterogeneity itself is well developed at a timescale as short as the $\beta$-relaxation time and survives up to a timescale as long as a few tens of the $\alpha$-relaxation time. Moreover, we discovered that the temperature dependence of the heterogeneity length remains the same in the whole time window, in agreement with the inhomogeneous mode-coupling theory, although its absolute value changes over time in a nonmonotonic manner.

中文翻译：

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过冷液体中颗粒位移及其时间演化的空间相关性中的动态异质性特征

过冷液体的动力学中存在异质性被认为是玻璃化转变的标志之一。过去已经进行了深入的研究，以了解这种异质性在动力学中的起源以及与之相关的可能的长度尺度。我们已经在三维上对几种模型玻璃成形液体进行了广泛的分子动力学模拟，以了解动态异质性和异质性长度尺度的时间演变。我们发现，尽管动态异质性的强度在接近特征的时间尺度上最大$\alpha$系统的松弛时间，动态异质性本身在短至 $\beta$松弛时间，并且可以保留长达数十年的时间尺度 $\alpha$-休息时间。此外，我们发现，尽管其绝对值以非单调方式随时间变化，但与非均匀模式耦合理论相一致，异质性长度的温度依赖性在整个时间窗口内保持不变。