发表机构
Nagoya University（名古屋大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过密度波方程和顶点修正，揭示了三层镍酸盐中短程自旋涨落的量子干涉产生轨道密度波，并协同稳定高温超导，提供了统一微观框架。
AI 中文摘要
相互交织的电荷密度波（CDW）和自旋密度波（SDW）序是高温超导多层镍酸盐的一个标志性特征。在三层La4Ni3O_{10}中，电荷关联在长程自旋序起始温度之上就已发展起来，其特征有序波矢满足$Q_{cdw} \approx 2Q_{sdw}$。在此，我们利用包含顶点修正的密度波方程，证明了在外层NiO2层上，$q \approx Q_{sdw}$处的短程SDW涨落之间的量子干涉会产生一个位于$Q_{cdw} \approx 2 Q_{sdw}$的外层间键序。这种键序诱导出显著的内层中心的轨道序，其中Ni $d_{3z^2-r^2}$和$d_{x^2-y^2}$占据呈现反相调制，产生强轨道极化但仅产生弱的总电荷调制。这种相互交织的键序和轨道序解释了从NMR/NQR推断出的层选择性电子重构，并与拉曼光谱和扫描隧道显微镜测量结果一致。相同的轨道和自旋涨落还通过$M_z$镜面宇称选择规则协同稳定$s_{\pm}$波超导电性。我们的结果为多层镍酸盐中相互交织的密度波序和高温超导电性提供了一个统一的微观框架。
英文摘要
Intertwined charge-density-wave (CDW) and spin-density-wave (SDW) orders are a hallmark of high-temperature superconducting multilayer nickelates. In trilayer La4Ni3O_{10}, charge correlations develop at temperatures above the onset of long-range spin order, and the characteristic ordering wavevectors satisfy $Q_{cdw} \approx 2Q_{sdw}$. Here, using a density-wave equation with vertex corrections, we show that quantum interference between short-range SDW fluctuations at $q \approx Q_{sdw}$ on the outer NiO2 layers generates an inter-outer-layer bond order at $Q_{cdw} \approx 2 Q_{sdw}$. This bond order induces a pronounced inner-layer-centered orbital order, with antiphase modulations of the Ni $d_{3z^2-r^2}$ and $d_{x^2-y^2}$ occupations, producing strong orbital polarization but only weak total charge modulation. This intertwined bond-and-orbital order accounts for the layer-selective electronic reconstruction inferred from NMR/NQR and is consistent with Raman spectroscopy and scanning tunnelling microscopy measurements. The same orbital and spin fluctuations also cooperate to stabilize $s_{\pm}$-wave superconductivity through $M_z$ mirror-parity selection rules. Our results provide a unified microscopic framework for intertwined density-wave order and high-Tc superconductivity in multilayer nickelates.
Comments19 pages, 10 figures
