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arXiv 1107.3928cond-mat.dis-nn
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玻璃形成液体动力学关联的非单调温度演化

Non-monotonic temperature evolution of dynamic correlations in glass-forming liquids

Walter Kob, Sandalo Roldan-Vargas, Ludovic Berthier

摘要:

如果玻璃形成液体的温度仅降低2-3倍,则其粘度增加许多数量级[1,2]。最近的研究表明,这种普遍现象伴随着空间非均匀动力学[3,4],以及量化相关粒子运动程度的动态相关长度不断增长[5-7]。在这里,我们使用一种新的数值方法来检测和量化的空间相关性,揭示了一个令人惊讶的非单调的温度演变的空间动力学相关性,伴随着第二个长度尺度,单调增长,具有非常不同的性质。我们的结果直接揭示了在模式耦合交叉温度附近原子运动的戏剧性质变[8],这不涉及拟合或间接的理论解释。我们的研究结果对玻璃化转变的理论描述施加了严格的新约束,并打开了几个研究视角,特别是对于实验,以确认和量化我们在实际材料中的观察结果。

英文摘要:

The viscosity of glass-forming liquids increases by many orders of magnitude if their temperature is lowered by a mere factor of 2-3 [1,2]. Recent studies suggest that this widespread phenomenon is accompanied by spatially heterogeneous dynamics [3,4], and a growing dynamic correlation length quantifying the extent of correlated particle motion [5-7]. Here we use a novel numerical method to detect and quantify spatial correlations which reveal a surprising non-monotonic temperature evolution of spatial dynamical correlations, accompanied by a second length scale that grows monotonically and has a very different nature. Our results directly unveil a dramatic qualitative change in atomic motions near the mode-coupling crossover temperature [8] which involves no fitting or indirect theoretical interpretation. Our results impose severe new constraints on the theoretical description of the glass transition, and open several research perspectives, in particular for experiments, to confirm and quantify our observations in real materials.

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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