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arXiv 1402.5974cond-mat.stat-mechcond-mat.soft
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用非晶壁探测过冷液体动力学中的交叉

Crossovers in the dynamics of supercooled liquids probed by an amorphous wall

Glen M Hocky, Ludovic Berthier, Walter Kob, David R. Reichman

摘要:

本文研究了二元Lennard-Jones液体在平衡态粒子组态产生的无定形壁存在下的弛豫动力学。与Nature Phys.{ \bf 8},164(2012)中针对谐波球液体呈现的结果定性一致,我们发现我们的二元混合物显示出接近模式耦合温度$T_c$的动力学长度尺度的饱和。此外,我们表明,由于破缺的对称性所施加的墙壁,签名的一个额外的动态变化变得明显的温度远高于$T_c$。我们提供的证据表明,这种修改的弛豫动力学发生在最近提出的动态交叉温度$T_s > T_c$,这是有关的斯托克斯-爱因斯坦关系的故障。我们发现,这种动态交叉在$T_s$也观察到一个系统的谐波球以及WCA液体,这表明它可能是一个一般功能的玻璃形成系统。

英文摘要:

We study the relaxation dynamics of a binary Lennard-Jones liquid in the presence of an amorphous wall generated from equilibrium particle configurations. In qualitative agreement with the results presented in Nature Phys. {\bf 8}, 164 (2012) for a liquid of harmonic spheres, we find that our binary mixture shows a saturation of the dynamical length scale close to the mode-coupling temperature $T_c$. Furthermore we show that, due to the broken symmetry imposed by the wall, signatures of an additional change in dynamics become apparent at a temperature well above $T_c$. We provide evidence that this modification in the relaxation dynamics occurs at a recently proposed dynamical crossover temperature $T_s > T_c$, which is related to the breakdown of the Stokes-Einstein relation. We find that this dynamical crossover at $T_s$ is also observed for a system of harmonic spheres as well as a WCA liquid, showing that it may be a general feature of glass-forming systems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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