论文标题
结构放松，软球液体中的动态逮捕和老化
Structural relaxation, dynamical arrest and aging in soft-sphere liquids
论文作者
论文摘要
我们在玻璃过渡上方和下方研究了不同温度$ t_f $ $ t_f $的软球液体淬火（$ ϕ = 0.7 $）的结构放松。为此，我们将广泛的布朗动力学模拟和理论计算结合在一起，基于非平衡自洽的广义Langevin方程（NE-SCGLE）理论。液体对淬火的反应通常包括随着系统年龄的增长$α$ - 递延时间的亚线性增加。从上方（$ t_f> t^a $）接近理想的玻璃过渡温度时，作为瞬态过程，描述了淬火到几乎被捕的状态的广泛平衡交叉。这使我们能够经验确定一个平衡时间尺度$ t^{eq}（t_f）$，随着$ t_f $接近$ t^a $，它变得越来越长。 For quenches inside the glass ($T_f\leq T^a$) the growth rate of the structural relaxation time becomes progressively larger as $T_f$ decreases and, unlike the equilibration scenario, $τ_α$ remains evolving within the whole observation time-window.These features are consistently found in theory and simulations with remarkable semi-quantitative agreement, and coincide with those revealed in the similar and complementary exercise [物理。修订版{\ bf 96}，022608（2017）]，它考虑了一系列具有固定最终温度的淬灭序列$ t_f = 0 $，但增加了$ ϕ $，以使硬球动态逮捕量$ ϕ^a__ {hs} = 0.582 $。但是，NE-SCGLE分析揭示了玻璃转变的各个基本方面，涉及从普通平衡场景到持续的衰老效应的突然传递，这些效果是玻璃形成液体的特征。该理论还解释说，在任何实验观察的时间窗口中，只能将其视为连续的交叉。
We investigate the structural relaxation of a soft-sphere liquid quenched isochorically ($ϕ=0.7$) and instantaneously to different temperatures $T_f$ above and below the glass transition. For this, we combine extensive Brownian dynamics simulations and theoretical calculations based on the non-equilibrium self-consistent generalized Langevin equation (NE-SCGLE) theory. The response of the liquid to a quench generally consists of a sub-linear increase of the $α$-relaxation time with system's age. Approaching the ideal glass-transition temperature from above ($T_f>T^a$) sub-aging appears as a transient process describing a broad equilibration crossover for quenches to nearly arrested states. This allows us to empirically determine an equilibration timescale $t^{eq}(T_f)$ that becomes increasingly longer as $T_f$ approaches $T^a$. For quenches inside the glass ($T_f\leq T^a$) the growth rate of the structural relaxation time becomes progressively larger as $T_f$ decreases and, unlike the equilibration scenario, $τ_α$ remains evolving within the whole observation time-window.These features are consistently found in theory and simulations with remarkable semi-quantitative agreement, and coincide with those revealed in the similar and complementary exercise [Phys. Rev. {\bf 96}, 022608 (2017)] that considered a sequence of quenches with fixed final temperature $T_f=0$ but increasing $ϕ$ towards the hard-sphere dynamical arrest volume fraction $ϕ^a_{HS}=0.582$. The NE-SCGLE analysis, however, unveils various fundamental aspects of the glass transition, involving the abrupt passage from the ordinary equilibration scenario to the persistent aging effects that are characteristic of glass-forming liquids. The theory also explains that, within the time window of any experimental observation, this can only be observed as a continuous crossover.
