Sun Gang, Xu Limei, Giovambattista Nicolas
International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.
School of Chemistry, University of Sydney, Sydney, New South Wales 2006, Australia.
Phys Rev Lett. 2018 Jan 19;120(3):035701. doi: 10.1103/PhysRevLett.120.035701.
We study the potential energy landscape (PEL) of a waterlike monatomic liquid that exhibits a liquid-liquid phase transition (LLPT) and glass-glass transformation (GGT). We identify two anomalous features of the PEL that give origin to both phenomena. Specifically, during the pressure-induced LLPT and GGT, (i) the inherent structures (IS) energy becomes a concave function of volume, and (ii) the IS pressure exhibits a van der Waals-like loop. We argue that features (i) and (ii) imply that the GGT is a (nonequilibrium) first-order phase transition, analogous to the LLPT. Interestingly, contrary to the case of the classical ST2 model for water, (a) we do not find two separate PEL megabasins (one for the low-density glass and liquid, and another for the high-density glass and liquid), and (b) features (i)-(ii) persist at temperatures well above the LLPT.
我们研究了一种呈现液-液相变（LLPT）和玻璃-玻璃转变（GGT）的类水单原子液体的势能面（PEL）。我们确定了PEL的两个异常特征，它们是这两种现象的起源。具体而言，在压力诱导的LLPT和GGT过程中，（i）固有结构（IS）能量成为体积的凹函数，并且（ii）IS压力呈现出类似范德瓦尔斯的回路。我们认为特征（i）和（ii）意味着GGT是一种（非平衡）一级相变，类似于LLPT。有趣的是，与经典水的ST2模型情况相反，（a）我们没有发现两个单独的PEL巨盆地（一个用于低密度玻璃和液体，另一个用于高密度玻璃和液体），并且（b）特征（i）-（ii）在远高于LLPT的温度下仍然存在。
