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arXiv 0904.1522cond-mat.dis-nn
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玻璃形成液体中的表面张力涨落和一个新的旋节点

Surface tension fluctuations and a new spinodal point in glass-forming liquids

C. Cammarota, A. Cavagna, G. Gradenigo, T. S. Grigera, P. Verrocchio

摘要:

玻璃形成液体的显着放缓已被不同地连接到增加动态和静态相关长度。然而,经验证据不足以在相互竞争的理论中做出决定。无规一阶理论(RFOT)链接的动态减速的增长无定形静态秩序,其范围取决于之间的平衡的构型熵和表面张力。当温度超过一个失稳点时,这最后一个量预计将消失,超过该失稳点就没有亚稳态。在这里,我们测量的表面张力在一个模型的玻璃形成器的第一次,并发现它消失的能量分离的最小值从鞍,证明存在一个亚稳秩序的非晶亚稳点。此外,表面张力的波动变得更小,为较低的温度,在定量协议与最近的理论推测,在玻璃体系中的空间相关性放松非指数,因为缩小的表面张力分布。

英文摘要:

The dramatic slowdown of glass-forming liquids has been variously linked to increasing dynamic and static correlation lengths. Yet, empirical evidence is insufficient to decide among competing theories. The random first order theory (RFOT) links the dynamic slowdown to the growth of amorphous static order, whose range depends on a balance between configurational entropy and surface tension. This last quantity is expected to vanish when the temperature surpasses a spinodal point beyond which there are no metastable states. Here we measure for the first time the surface tension in a model glass-former, and find that it vanishes at the energy separating minima from saddles, demonstrating the existence of a spinodal point for amorphous metastable order. Moreover, the fluctuations of surface tension become smaller for lower temperatures, in quantitative agreement with recent theoretical speculation that spatial correlations in glassy systems relax nonexponentially because of the narrowing of the surface tension distribution.

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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