论文标题
Kob-Andersen型玻璃板中的局部订购波动
Local-order fluctuations in Kob-Andersen-type glass formers
论文作者
论文摘要
尽管有数十年的工作，但我们仍然缺乏对当液体迅速冷却以形成玻璃的结构放松的令人满意的理解。本文讨论了在Kob-Andersen型混合物中对这种现象的新统计表征 - 一种简单而强大的模型玻璃板组。我们使用称为肺外系数的顺序参数的方差来测量局部定向顺序的瞬时波动的强度。在标准的Kob-Andersen混合物的玻璃动力学开始温度下，发现这种强度几乎独立于组成。我们将这些波动分解为密度和对称性贡献。通过这些贡献的行为，我们认为当系统的结构相似于液体和玻璃时，近乎组成的独立性就会占上风。此外，我们还报告说，局部波动的强度就像玻璃形成能力的启发式量度一样，当确切的方法棘手时，这可能证明是有用的。
Notwithstanding decades of work, we still lack a satisfactory understanding of the structural relaxation that takes place as a liquid is rapidly cooled to form a glass. The present paper discusses a novel statistical characterization of this phenomenon in Kob-Andersen-type mixtures -- a simple yet powerful class of model glass formers. We use the variance of an order parameter called the extracopularity coefficient to measure the intensity of instantaneous fluctuations in local orientational order. This intensity is found to be nearly composition independent at the onset temperature of glassy dynamics for the standard Kob-Andersen mixture. We decompose these fluctuations into a density and symmetry contribution. Through the behavior of these contributions, we argue that the near composition independence prevails when the structure of the system equally resembles a liquid and a glass. We moreover report that the intensity of local-order fluctuations behaves like a heuristic measure of glass-forming ability, which could prove useful when exact methods are intractable.
