Free-energy landscape of simple liquids near the glass transition
Free-energy landscape of simple liquids near the glass transition
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DOI：
10.1088/0953-8984/12/29/327
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发表时间：
2000-07-24
影响因子：
2.7
通讯作者：
Valls, OT
中科院分区：
文献类型：
--
作者：
Dasgupta, C;Valls, OT
数值研究了稠密硬球系统相空间中的自由能景观的性质，其特征在于离散化的Ramakrishnan-Yussouff形式的自由能泛函。相当数量的玻璃的自由能的局部极小值的位置和适当定义的“重叠”极小值之间的分布计算。过渡的过程中，从盆地的吸引力的最小的另一个研究使用一个新的“微正则”蒙特卡罗程序，导致确定的有效高度的自由能障碍，分离不同的玻璃极小。自由能源景观的总体外观类似于一个推杆绿色：深深的极小值被一个相当大的老鼠结构分开。随着密度的增加，有效自由能势垒的增长与Vogel-Fulcher定律一致，并且这种增长主要是由熵机制驱动的。
Properties of the free-energy landscape in phase space of a dense hard-sphere system characterized by a discretized free-energy functional of the Ramakrishnan-Yussouff form are investigated numerically. A considerable number of glassy local minima of the free energy are located and the distribution of an appropriately defined 'overlap' between minima is calculated. The process of transition from the basin of attraction of a minimum to that of another one is studied using a new 'microcanonical' Monte Carlo procedure, leading to a determination of the effective height of free-energy barriers that separate different glassy minima. The general appearance of the free-energy landscape resembles that of a putting green: deep minima separated by a fairly Rat structure. The growth of the effective free-energy barriers with increasing density is consistent with the Vogel-Fulcher law, and this growth is primarily driven by an entropic mechanism.