Li Bo, Lee Chun-Shing, Gao Xin-Yuan, Deng Hai-Yao, Lam Chi-Hang
School of Science, Harbin Institute of Technology (Shenzhen), Shenzhen, 518055, China.
Department of Applied Physics, Hong Kong Polytechnic University, Hung Hom, Hong Kong, China.
Soft Matter. 2024 Jan 31;20(5):1009-1017. doi: 10.1039/d3sm01343j.
The nature of glassy states in realistic finite dimensions is still under fierce debate. Lattice models can offer valuable insights and facilitate deeper theoretical understanding. Recently, a disordered-interacting lattice model with distinguishable particles in two dimensions (2D) has been shown to produce a wide range of dynamical properties of structural glasses, including the slow and heterogeneous characteristics of the glassy dynamics, various fragility behaviors of glasses, and so on. These findings support the usefulness of this model for modeling structural glasses. An important question is whether such properties still hold in the more realistic three dimensions. In this study, we aim to extend the distinguishable-particle lattice model (DPLM) to three dimensions (3D) and explore the corresponding glassy dynamics. Through extensive kinetic Monte Carlo simulations, we found that the 3D DPLM exhibits many typical glassy behaviors, such as plateaus in the mean square displacement of particles and the self-intermediate scattering function, dynamic heterogeneity, variability of glass fragilities, and so on, validating the effectiveness of the DPLM in a broader realistic setting. The observed glassy behaviors of the 3D DPLM appear similar to those of its 2D counterpart, in accordance with recent findings in molecular models of glasses. We further investigate the role of void-induced motions in dynamical relaxations and discuss their relation to dynamic facilitation. As lattice models tend to keep the minimal but important modeling elements, they are typically much more amenable to analysis. Therefore, we envisage that the DPLM will benefit future theoretical developments, such as the configuration tree theory, towards a more comprehensive understanding of structural glasses.
现实有限维度中玻璃态的本质仍处于激烈的争论之中。晶格模型能够提供有价值的见解，并有助于加深理论理解。最近，一种二维（2D）中具有可区分粒子的无序相互作用晶格模型已被证明能够产生结构玻璃的广泛动力学性质，包括玻璃态动力学的缓慢和非均匀特性、玻璃的各种脆性行为等等。这些发现支持了该模型在模拟结构玻璃方面的实用性。一个重要的问题是，这些性质在更现实的三维中是否仍然成立。在本研究中，我们旨在将可区分粒子晶格模型（DPLM）扩展到三维（3D），并探索相应的玻璃态动力学。通过广泛的动力学蒙特卡罗模拟，我们发现三维DPLM表现出许多典型的玻璃态行为，例如粒子的均方位移和自中间散射函数中的平台、动态非均匀性、玻璃脆性的变化等等，这验证了DPLM在更广泛现实环境中的有效性。三维DPLM观察到的玻璃态行为与其二维对应物的行为相似，这与玻璃分子模型中的最新发现一致。我们进一步研究了空位诱导运动在动态弛豫中的作用，并讨论了它们与动态促进的关系。由于晶格模型倾向于保留最少但重要的建模元素，它们通常更易于分析。因此，我们设想DPLM将有利于未来的理论发展，例如构型树理论，以更全面地理解结构玻璃。
