Rubner Oliver, Heuer Andreas
Institute of Physical Chemistry, University of Münster, Corrensstrasse 30, Münster, Germany.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Jul;78(1 Pt 1):011504. doi: 10.1103/PhysRevE.78.011504. Epub 2008 Jul 21.
We show that the dynamics of supercooled liquids, analyzed from computer simulations of the binary mixture Lennard-Jones system, can be described in terms of a continuous-time random walk (CTRW). The required discretization comes from mapping the dynamics on transitions between metabasins. This yields a quantitative link between the elementary step and the full structural relaxation. The analysis involves a verification of the CTRW conditions as well as a quantitative test of the predictions. The wave-vector dependence of the relaxation time and the degree of nonexponentiality can be expressed in terms of the first moments of the waiting time distribution.
我们表明，通过对二元混合 Lennard-Jones 系统的计算机模拟分析，过冷液体的动力学可以用连续时间随机游走（CTRW）来描述。所需的离散化来自于将动力学映射到亚稳态之间的转变上。这在基本步长和完全结构弛豫之间建立了定量联系。该分析包括对 CTRW 条件的验证以及对预测的定量测试。弛豫时间和非指数程度的波矢依赖性可以根据等待时间分布的一阶矩来表示。
