Doliwa B, Heuer A
Max Planck Institute for Polymer Research, Mainz, Germany.
Phys Rev Lett. 2003 Dec 5;91(23):235501. doi: 10.1103/PhysRevLett.91.235501. Epub 2003 Dec 2.
For a model glass former we demonstrate via computer simulations how macroscopic dynamic quantities can be inferred from a potential energy landscape (PEL) analysis. The essential step is to consider whole superstructures of many PEL minima, called metabasins, rather than single minima. We show that two types of metabasins exist: some allowing for quasifree motion on the PEL (liquidlike), and the others acting as traps (solidlike). The activated, multistep escapes from the latter metabasins are found to dictate the slowing down of dynamics upon cooling over a much broader temperature range than is currently assumed.
对于一个典型的玻璃形成体，我们通过计算机模拟展示了如何从势能面（PEL）分析中推断宏观动力学量。关键步骤是考虑许多PEL极小值的整个超结构，即所谓的亚稳盆地，而不是单个极小值。我们发现存在两种类型的亚稳盆地：一些允许在PEL上进行准自由运动（类似液体），而另一些则充当陷阱（类似固体）。我们发现，在比目前所假设的更宽的温度范围内，从后一种亚稳盆地的激活、多步逃逸决定了冷却过程中动力学的减慢。
