School of Chemistry, Beihang University, Beijing 100191, China.
Center of Soft Matter Physics and Its Applications, Beihang University, Beijing 100191, China.
Proc Natl Acad Sci U S A. 2021 Mar 16;118(11). doi: 10.1073/pnas.2017392118.
Apparent critical phenomena, typically indicated by growing correlation lengths and dynamical slowing down, are ubiquitous in nonequilibrium systems such as supercooled liquids, amorphous solids, active matter, and spin glasses. It is often challenging to determine if such observations are related to a true second-order phase transition as in the equilibrium case or simply a crossover and even more so to measure the associated critical exponents. Here we show that the simulation results of a hard-sphere glass in three dimensions are consistent with the recent theoretical prediction of a Gardner transition, a continuous nonequilibrium phase transition. Using a hybrid molecular simulation-machine learning approach, we obtain scaling laws for both finite-size and aging effects and determine the critical exponents that traditional methods fail to estimate. Our study provides an approach that is useful to understand the nature of glass transitions and can be generalized to analyze other nonequilibrium phase transitions.
明显的临界现象，通常表现为关联长度的增长和动力学的减缓，在非平衡系统中无处不在，如过冷液体、非晶固体、活性物质和自旋玻璃。通常很难确定这些观察结果是否与平衡情况下的真正二阶相变有关，或者仅仅是交叉，更难测量相关的临界指数。在这里，我们表明，在三维硬球玻璃的模拟结果与最近关于 Gardner 转变的理论预测一致，这是一种连续的非平衡相变。我们使用混合分子模拟-机器学习方法，获得了有限大小和老化效应的标度律，并确定了传统方法无法估计的临界指数。我们的研究提供了一种理解玻璃转变性质的方法，并且可以推广到分析其他非平衡相变。
