Liao C Y, Chen S H
Department of Nuclear Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2001 Sep;64(3 Pt 1):031202. doi: 10.1103/PhysRevE.64.031202. Epub 2001 Aug 27.
We present a description of the dynamics of a supercooled binary Lennard-Jones liquid in term of the potential landscape of the system. The slowing down of the dynamics in supercooled liquids near the kinetic glass transition is related to the existence of basins in the potential landscape. The inherent structures that are the local potential minima in the configuration space obtained by a quench process are employed to represent the configurations of the basins. We present time correlation functions of the inherent structure, both the self and the coherent part, as a function of wave vector. We also calculated the mean-square displacement, and the non-Gaussian parameter of the van Hove self-correlation function. Compared with the dynamics of original configurations, the short-time relaxation has almost been eliminated by the quench process. However, the long-time alpha relaxations remain essentially the same. We conclude that the long-time alpha relaxation is the result of cross-basin transition in the potential landscape in the configuration space.
我们根据系统的势能面描述了过冷二元 Lennard-Jones 液体的动力学。在动力学玻璃化转变附近过冷液体中动力学的减慢与势能面中盆地的存在有关。通过淬火过程在构型空间中得到的作为局部势能极小值的固有结构被用来表示盆地的构型。我们给出了固有结构的时间关联函数，包括自关联部分和相干部分，作为波矢的函数。我们还计算了均方位移和 van Hove 自关联函数的非高斯参数。与原始构型的动力学相比，淬火过程几乎消除了短时间弛豫。然而，长时间的α弛豫基本保持不变。我们得出结论，长时间的α弛豫是构型空间中势能面跨盆地转变的结果。
