Assessing the role of static length scales behind glassy dynamics in polydisperse hard disks
Assessing the role of static length scales behind glassy dynamics in polydisperse hard disks
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DOI：
10.1073/pnas.1501911112
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发表时间：
2015-06-02
影响因子：
11.1
通讯作者：
Tanaka, Hajime
中科院分区：
文献类型：
--
作者：
Russo, John;Tanaka, Hajime
增长的静态秩序中的动态减慢向玻璃化转变的可能作用最近引起了相当大的关注。基于随机一级跃迁理论，提出了一种新的测量非晶有序静态关联长度的方法，称为“点到集”（PTS）长度，并证明了非晶有序的动态关联长度比静态关联长度增长得快得多。在这里，我们研究的PTS长度的性质，使用多分散的硬盘系统，这是一个模型，是已知的致密化后表现出不断增长的六角形秩序。我们发现，PTS相关长度是解耦的六阶和动态异质性的相关长度的急剧增加，同时密切反映两体密度相关的衰减长度。因此，我们的研究结果提供了一个明确的例子，其他形式的秩序可以发挥重要作用，在减慢的动态，铸造一个严重的怀疑的顺序不可知论性质的PTS长度和其相关性缓慢的动态，提供了一个多分散的硬盘系统是一个典型的玻璃前体。
The possible role of growing static order in the dynamical slowing down toward the glass transition has recently attracted considerable attention. On the basis of random first-order transition theory, a new method to measure the static correlation length of amorphous order, called "point-to-set" (PTS) length, has been proposed and used to show that the dynamic length grows much faster than the static length. Here, we study the nature of the PTS length, using a polydisperse hard-disk system, which is a model that is known to exhibit a growing hexatic order upon densification. We show that the PTS correlation length is decoupled from the steeper increase of the correlation length of hexatic order and dynamic heterogeneity, while closely mirroring the decay length of two-body density correlations. Our results thus provide a clear example that other forms of order can play an important role in the slowing down of the dynamics, casting a serious doubt on the order-agnostic nature of the PTS length and its relevance to slow dynamics, provided that a polydisperse hard-disk system is a typical glass former.