Jack Robert L, Berthier Ludovic
Department of Physics, University of Bath, Bath BA2 7AY, United Kingdom.
Laboratoire Charles Coulomb, UMR 5221 CNRS-Université de Montpellier, 34095 Montpellier, France.
J Chem Phys. 2016 Jun 28;144(24):244506. doi: 10.1063/1.4954327.
We discuss the microscopic mechanisms by which low-temperature amorphous states, such as ultrastable glasses, transform into equilibrium fluids, after a sudden temperature increase. Experiments suggest that this process is similar to the melting of crystals, thus differing from the behaviour found in ordinary glasses. We rationalize these observations using the physical idea that the transformation process takes place close to a "hidden" equilibrium first-order phase transition, which is observed in systems of coupled replicas. We illustrate our views using simulation results for a simple two-dimensional plaquette spin model, which is known to exhibit a range of glassy behaviour. Our results suggest that nucleation-and-growth dynamics, as found near ordinary first-order transitions, is also the correct theoretical framework to analyse the melting of ultrastable glasses. Our approach provides a unified understanding of multiple experimental observations, such as propagating melting fronts, large kinetic stability ratios, and "giant" dynamic length scales. We also provide a comprehensive discussion of available theoretical pictures proposed in the context of ultrastable glass melting.
我们讨论了低温非晶态（如超稳定玻璃）在温度突然升高后转变为平衡流体的微观机制。实验表明，这个过程类似于晶体的熔化，因此不同于普通玻璃中的行为。我们利用这样一个物理观点来解释这些观察结果，即转变过程发生在一个“隐藏”的平衡一级相变附近，这在耦合副本系统中可以观察到。我们用一个简单的二维格子自旋模型的模拟结果来说明我们的观点，该模型已知会表现出一系列玻璃态行为。我们的结果表明，在普通一级相变附近发现的成核与生长动力学，也是分析超稳定玻璃熔化的正确理论框架。我们的方法为多种实验观察结果提供了统一的理解，比如传播的熔化前沿、大的动力学稳定性比以及“巨大”的动态长度尺度。我们还对超稳定玻璃熔化背景下提出的现有理论图景进行了全面讨论。
