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arXiv 1203.3166cond-mat.stat-mechcond-mat.dis-nn
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玻璃动力学的动力学约束模型与无规一级相变理论的关系

On the relation between kinetically constrained models of glass dynamics and the random first-order transition theory

Laura Foini, Florent Krzakala, Francesco Zamponi

摘要:

在本文中,我们重新审视和扩展两个明显不同的模型类之间的映射。第一类包含的原型模型描述-在平均场水平-由随机一级跃迁(RFOT)理论的玻璃化转变,称为“随机XORSAT问题”(在信息理论界)或“稀释$p$ -自旋模型”(在自旋玻璃社区),经历一个单自旋翻转Glauber动力学。第二类模型是动力学约束模型(KCM):它们的哈密顿量是恒定磁场中的独立自旋的哈密顿量,因此它们的热力学是完全平凡的,但动力学是这样的,只有自旋组可以一起翻转,从而实现动力学约束,引起非平凡的动力学行为。这两个类的一些代表之间的映射已经知道很久了。在这里,我们正式证明这个映射的水平上的主方程,我们将其应用到特定的情况下,贝特格模型。这使我们能够证明RFOT模型可以精确地映射到KCM。然而,RFOT模型的自然序参量,即自旋重叠,在KCM中被映射成非常复杂的非局部函数。因此,如果一个人在不知道映射到RFOT模型的情况下研究KCM,他会猜测它的物理学与RFOT模型完全不同。相反,我们的研究结果表明,这两个明显不同的玻璃化转变的描述,至少在某些情况下,密切相关。

英文摘要:

In this paper we revisit and extend the mapping between two apparently different classes of models. The first class contains the prototypical models described --at the mean-field level-- by the Random First Order Transition (RFOT) theory of the glass transition, called either "random XORSAT problem" (in the information theory community) or "diluted $p$-spin model" (in the spin glass community), undergoing a single-spin flip Glauber dynamics. The models in the second class are Kinetically Constrained Models (KCM): their Hamiltonian is that of independent spins in a constant magnetic field, hence their thermodynamics is completely trivial, but the dynamics is such that only groups of spin can flip together, thus implementing a kinetic constraint that induces a non-trivial dynamical behavior. A mapping between some representatives of these two classes has been known for long. Here we formally prove this mapping at the level of the master equation, and we apply it to the particular case of Bethe lattice models. This allows us to show that a RFOT model can be mapped exactly into a KCM. However, the natural order parameter for the RFOT model, namely the spin overlap, is mapped into a very complicated non-local function in the KCM. Therefore, if one were to study the KCM without knowing of the mapping onto the RFOT model, one would guess that its physics is quite different from the RFOT one. Our results instead suggest that these two apparently different descriptions of the glass transition are, at least in some case, closely related.

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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