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arXiv math-ph/0405024math-phcond-mat.dis-nnmath.MP
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无规聚合物模型中的离域性

Delocalization in random polymer models

S. Jitomirskaya, H. Schulz-Baldes, G. Stolz

摘要:

随机聚合物模型是由两个有限构建块随机组成的一维雅可比矩阵。如果两个相关的传递矩阵可交换,则相应的能量称为临界能量。这样的临界能量出现在物理模型中,一个例子是广泛研究的随机二聚体模型。证明了李雅普诺夫指数在一般的临界能量处二次地为零,并且态密度在那里为正。这些渐近的大偏差估计允许证明量子输运的最佳下限,表明它几乎肯定是过度扩散的,即使模型是已知的,几乎每一个配置的聚合物具有纯点光谱与指数本地化的本征态。此外,能级间距被证明是规则的临界能量。

英文摘要:

A random polymer model is a one-dimensional Jacobi matrix randomly composed of two finite building blocks. If the two associated transfer matrices commute, the corresponding energy is called critical. Such critical energies appear in physical models, an example being the widely studied random dimer model. It is proven that the Lyapunov exponent vanishes quadratically at a generic critical energy and that the density of states is positive there. Large deviation estimates around these asymptotics allow to prove optimal lower bounds on quantum transport, showing that it is almost surely overdiffusive even though the models are known to have pure-point spectrum with exponentially localized eigenstates for almost every configuration of the polymers. Furthermore, the level spacing is shown to be regular at the critical energy.

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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