Beijing Computational Science Research Center, Beijing 100193, People's Republic of China.
CAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at the Microscale and Department of Physics, University of Science and Technology of China, Hefei 230026, People's Republic of China.
Phys Rev Lett. 2018 Mar 23;120(12):125502. doi: 10.1103/PhysRevLett.120.125502.
Despite the use of glasses for thousands of years, the nature of the glass transition is still mysterious. On approaching the glass transition, the growth of dynamic heterogeneity has long been thought to play a key role in explaining the abrupt slowdown of structural relaxation. However, it still remains elusive whether there is an underlying link between structural relaxation and dynamic heterogeneity. Here, we unravel the link by introducing a characteristic time scale hiding behind an identical dynamic heterogeneity for various model glass-forming liquids. We find that the time scale corresponds to the kinetic fragility of liquids. Moreover, it leads to scaling collapse of both the structural relaxation time and dynamic heterogeneity for all liquids studied, together with a characteristic temperature associated with the same dynamic heterogeneity. Our findings imply that studying the glass transition from the viewpoint of dynamic heterogeneity is more informative than expected.
尽管眼镜已经使用了数千年，但玻璃化转变的本质仍然神秘莫测。在接近玻璃化转变时，动态异质性的增长长期以来被认为在解释结构弛豫的突然减慢方面起着关键作用。然而，结构弛豫和动态异质性之间是否存在潜在联系仍然难以捉摸。在这里，我们通过引入一个隐藏在各种模型玻璃形成液体相同动态异质性背后的特征时间尺度来揭示这种联系。我们发现该时间尺度与液体的动力学脆性相对应。此外，它导致所有研究液体的结构弛豫时间和动态异质性的标度崩溃，以及与相同动态异质性相关的特征温度。我们的发现表明，从动态异质性的角度研究玻璃化转变比预期的更有信息量。
