论文标题
多体系统中量子混沌发作的普遍性
Universality in the onset of quantum chaos in many-body systems
论文作者
论文摘要
我们表明，在两个多体温度的一维晶格模型（即扰动的旋转1/2 XXZ和安德森模型）中，量子混乱在无限温度下的发作以普遍的行为为特征。具体而言，我们表明，量子混乱的发作是由典型的忠诚度敏感性的最大值，这些敏感性与平均水平逆水平间距的平方缩放，使其上限饱和，以及在这些最大值下降低的可集成性或定位性破坏的强度随着系统的增加而减小。我们还表明，在接近这些最大值时，``无''能量（在量子 - 偶然状态中）下方的光谱函数会出现差异。我们的结果表明，在热力学极限下，任意小的可集成性或破坏定位的扰动导致此处研究的多体量子系统中的量子混乱。
We show that the onset of quantum chaos at infinite temperature in two many-body one-dimensional lattice models, the perturbed spin-1/2 XXZ and Anderson models, is characterized by universal behavior. Specifically, we show that the onset of quantum chaos is marked by maxima of the typical fidelity susceptibilities that scale with the square of the inverse average level spacing, saturating their upper bound, and that the strength of the integrability- or localization-breaking perturbation at these maxima decreases with increasing system size. We also show that the spectral function below the ``Thouless'' energy (in the quantum-chaotic regime) diverges when approaching those maxima. Our results suggest that, in the thermodynamic limit, arbitrarily small integrability- or localization-breaking perturbations result in quantum chaos in the many-body quantum systems studied here.
