张-赖斯范式之外铜酸盐梯子中的轨道选择氧空穴
Orbital-selective oxygen holes in cuprate ladders beyond the Zhang-Rice paradigm
AI总结：
该研究结合偏振依赖共振软X射线散射与非弹性中子散射，揭示了自旋梯子型铜酸盐Sr14Cu24O41的掺杂空穴定域于特定氧轨道，挑战了张-赖斯单重态框架，为铜酸盐超导体研究提供了新视角。
AI中文摘要：
自旋梯子型铜酸盐Sr14Cu24O41的电子结构对张-赖斯单重态（ZRS）框架及仅基于铜-氧杂化轨道的模型的假定普适性提出了挑战。结合氧K边的偏振依赖共振软X射线散射（RSXS）与非弹性中子散射，我们发现Cu2O3梯子中的掺杂空穴主要定域在梯级氧位点的平面非键合O 2pz（pπ）轨道中，而非形成常规ZRS态。偏振分辨RSXS明确识别了该轨道归属，而晶格与磁激发揭示了其耦合后果，构建了排除常规σ键合单重态的统一微观图像。这种氧亚晶格电荷有序产生了异常的对角拉伸声子，解释了非公度磁涨落及异常磁振子分裂的缺失。这些发现促使重新评估梯子型铜酸盐中的空穴配对，以及以铜为中心的铜酸盐超导体模型的充分性。
英文摘要：
The electronic structure of the spin-ladder cuprate Sr14Cu24O41 challenges the presumed universality of the Zhang-Rice singlet (ZRS) framework and models based exclusively on Cu-O hybridized orbitals. Combining polarization-dependent resonant soft X-ray scattering at the O K-edge with inelastic neutron scattering, we show that doped holes in the Cu2O3 ladders localize predominantly in planar non-bonding O 2pz (pπ) orbitals of rung oxygen sites rather than forming conventional ZRS states. Polarization-resolved RSXS uniquely identifies this orbital assignment, while lattice and magnetic excitations reveal its coupled consequences, establishing a unified microscopic picture that excludes the conventional σ-bonded singlet. This oxygen-sublattice charge order produces an anomalous diagonal stretching phonon and explains the absence of incommensurate magnetic fluctuations and anomalous magnon splitting. These findings motivate a reassessment of hole pairing in ladder cuprates and the sufficiency of copper-centric models for cuprate superconductors.
