By means of Cu K edge x-ray absorption spectra of overdoped high-pressure oxygenated superconducting YSr2Cu2.75Mo0.25O7.54 and Sr2CuO3.3 , we demonstrate a remarkably strong three way correlation between the superconductivity and the local dynamics of their highly anharmonic Cu–Sr and Cu-apical O pairs. We model the latter as aspects of the Internal Quantum Tunneling Polarons (IQTPs) that give the two-site distributions in extended x-ray absorption fine structure and inelastic pair distribution function measurements. This finding obviates the common assumption that the universal Ba/Sr-apical O dielectric layer, far from only maintaining the separation of charges between the charge reservoir and the CuO2 conducting domains, plays an unexpectedly active role in the unusual electronic properties of cuprate superconductors. Furthermore, we investigate the effects of the dynamic structure associated with these pairs by means of the exact diagonalization of a prototype Hamiltonian based on a six-atom cluster, with two neighboring Cu-apical O pairs bridged by an anharmonically coupled Sr atom and a planar O atom. In terms of the Kuramoto model for synchronization, these calculations show a first order phase transition, driven by anharmonicity, to a synchronized state of the IQTPs, in which a fraction of the charge originally confined to the apical O sites is transferred onto the planar O in the superconducting plane. This combination of experimental results and theory demonstrates that the Ba/Sr-apical O layer of cuprates most likely plays an important role in high temperature superconductivity via its collective charge dynamics.

中文翻译：

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锶非谐性与顶氧电荷晶格动力学的相关性及其与铜酸盐超导性的耦合

过掺杂高压含氧超导的Cu K边X射线吸收光谱 是Sr2C你2.75中号哦0.25氧7.54 和 Sr2C你氧3.3 ，我们证明了超导性和高度非谐 Cu-Sr 和 Cu-顶端 O 对的局部动力学之间存在非常强的三向相关性。我们将后者建模为内部量子隧道极化子 (IQTP) 的各个方面，它给出了扩展 X 射线吸收精细结构和非弹性对分布函数测量中的双位点分布。这一发现消除了普遍的假设，即通用 Ba/Sr-顶端 O 介电层远非仅仅维持电荷储存器和电荷之间的电荷分离。 C你氧2 导电域，在铜酸盐超导体的异常电子特性中发挥着意想不到的积极作用。此外，我们通过基于六原子簇的原型哈密顿量的精确对角化来研究与这些对相关的动态结构的影响，其中两个相邻的 Cu 顶端 O 对通过非和谐耦合的 Sr 原子和平面桥接O原子。就同​​步的 Kuramoto 模型而言，这些计算显示了由非谐性驱动的一阶相变到 IQTP 的同步状态，其中最初限制在顶端 O 位点的一小部分电荷转移到平面 O 上在超导平面中。实验结果和理论的结合表明，铜酸盐的 Ba/Sr-顶端 O 层很可能通过其集体电荷动力学在高温超导中发挥重要作用。