We study a two-dimensional glass-forming system of slightly polydisperse (LJ) particles using molecular dynamics simulations and demonstrate that in the liquid regime (well above the vitrification temperature) this model shows a number of features typical of the glass transition: (i) the relation between compressibility and structure factor $S\left(q\right)$ is strongly violated; (ii) the dynamical structure factor $S(q,t)$ at low $q$ shows a two-step relaxation; (iii) the time-dependent heat capacity $c_v\left(t\right)$ shows a long-time power-law tail. We show that these phenomena can be rationalized with the idea of composition fluctuations and provide a quantitative theory for the effects (i) and (ii). It implies that such effects must be inherent in all polydisperse colloidal models, including binary LJ mixtures.

中文翻译：

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多分散液体中的成分波动：玻璃样效果远高于玻璃化转变温度

我们使用分子动力学模拟研究了微分散（LJ）颗粒的二维玻璃形成系统，并证明在液体状态（远高于玻璃化温度）下，该模型显示出许多玻璃化转变的典型特征：压缩率与结构因子之间的关系 $\mathrm{小号}（q）$受到严重侵犯；（ii）动力结构因素$\mathrm{小号}（q，Ť）$ 低 $q$显示两步放松；（iii）随时间变化的热容量$C_v（Ť）$显示了很长的幂律尾巴。我们表明，可以用成分波动的思想使这些现象合理化，并为效应（i）和（ii）提供定量理论。这意味着这种影响必须在所有多分散胶体模型中都固有，包括二元LJ混合物。