论文标题
深层神经网络在玻璃的无序结构中发现了什么?
What Do Deep Neural Networks Find in Disordered Structures of Glasses?
论文作者
论文摘要
在各种类型的软物质系统中广泛观察到玻璃转变。然而,尽管有多年的研究,这些过渡的物理机制仍然是{难以捉摸的}。特别是,一个重要的未解决的问题是玻璃转变是否伴随着特征静态结构的相关长度的分歧。在这项研究中,我们开发了一种基于深神经网络的方法,该方法用于仅从瞬时{粒子}配置中提取特征性的局部中间结构,而无需任何有关动力学的{信息}。我们首先训练神经网络以正确对液体和眼镜的配置进行分类。然后,我们通过使用梯度加权类激活映射(GRAD-CAM)来量化网络做出的决策来获得特征结构。我们考虑了两个定性不同的玻璃形成二进制系统,并通过与几个既定结构指标进行比较,我们证明我们的系统可用于识别取决于系统细节的特征结构。此外,提取的结构与热波动中的非平衡衰老动力学显着相关。
Glass transitions are widely observed in various types of soft matter systems. However, the physical mechanism of these transitions remains {elusive}, despite years of ambitious research. In particular, an important unanswered question is whether the glass transition is accompanied by a divergence of the correlation lengths of the characteristic static structures. In this study, we develop a deep-neural-network-based method that is used to extract the characteristic local meso-structures solely from instantaneous {particle} configurations without any {information} about the dynamics. We first train a neural network to classify configurations of liquids and glasses correctly. Then, we obtain the characteristic structures by quantifying the grounds for the decisions made by the network using Gradient-weighted Class Activation Mapping (Grad-CAM). We considered two qualitatively different glass-forming binary systems, and through comparisons with several established structural indicators, we demonstrate that our system can be used to identify characteristic structures that depend on the details of the systems. Moreover, the extracted structures are remarkably correlated with the nonequilibrium aging dynamics in thermal fluctuations.