Theory for the single-particle dynamics in glassy mixtures with particle size swaps
Theory for the single-particle dynamics in glassy mixtures with particle size swaps
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DOI：
10.1088/1742-5468/ab2904
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发表时间：
2019-02
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影响因子：
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通讯作者：
G. Szamel
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文献类型：
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作者：
G. Szamel
本文提出了一个具有粒径交换的二元混合物单粒子动力学理论。该理论的一般结构遵循我们以前开发的具有颗粒尺寸交换的二元混合物中的集体动力学理论（Szamel 2018 Phys. Rev. E 98 050601）。粒子大小交换打开了一个额外的弛豫通道，这加快了集体动力学和单粒子动力学。为了作出明确的预测，我们诉诸于类似的模式耦合理论的玻璃动力学的因式分解近似。我们表明，像在标准模式耦合理论，单粒子运动成为逮捕在动态玻璃化转变预测的集体动力学理论。我们比较了非遍历参数预测我们的模式耦合的方法，为等摩尔的二元硬球混合物的颗粒大小的交换与非遍历参数预测的标准模式耦合理论相同的系统没有交换。我们的理论预测，“笼大小”是更大的系统中的颗粒尺寸交换。
We present a theory for the single-particle dynamics in binary mixtures with particle size swaps. The general structure of the theory follows that of the theory for the collective dynamics in binary mixtures with particle size swaps, which we developed previously (Szamel 2018 Phys. Rev. E 98 050601). Particle size swaps open up an additional relaxation channel, which speeds up both the collective dynamics and the single-particle dynamics. To make explicit predictions, we resort to a factorization approximation similar to that employed in the mode-coupling theory of glassy dynamics. We show that, like in the standard mode-coupling theory, the single-particle motion becomes arrested at the dynamic glass transition predicted by the theory for the collective dynamics. We compare the non-ergodicity parameters predicted by our mode-coupling-like approach for an equimolar binary hard sphere mixture with particle size swaps with the non-ergodicity parameters predicted by the standard mode-coupling theory for the same system without swaps. Our theory predicts that the ‘cage size’ is bigger in the system with particle size swaps.