标题： 三层镍氧化物中与密度波序交织的晶格电荷耦合 显示英文标题

标题： Lattice-charge coupling in a trilayer nickelate with intertwined density wave order

摘要： 纠缠的电荷和自旋关联在广泛的过渡金属氧化物中普遍存在，并常被认为与非常规超导性密切相关。 理论上认为这种纠缠序是由强电子关联驱动的，通常发现它与晶格强烈耦合，这由明显的声子软化所表明。 最近，在几种Ruddlesden-Popper（RP）镍氧化物中，包括三层镍氧化物RE4Ni3O10（RE=Pr, La），已经发现了电荷/自旋密度波（CDW/SDW）和超导性。 纠缠序的本质以及晶格-电荷耦合的作用是关于这些材料争论的核心。 使用非弹性X射线散射，我们绘制了RE4Ni3O10中的声子色散，并在宽温度范围内没有在CDW波矢附近发现声子软化的证据。 电子敏感度的计算显示在观察到的SDW有序矢量处有一个峰值，但不在CDW波矢处。 声子软化的缺失与典型氧化物材料，特别是铜氧化物中的情况形成鲜明对比。 我们的实验和理论结果强调了自旋自由度的关键作用，并为理解RP镍氧化物超导体中超导性和密度波转变之间的相互作用奠定了基础。 显示英文摘要

摘要： Intertwined charge and spin correlations are ubiquitous in a wide range of transition metal oxides and are often perceived as intimately related to unconventional superconductivity. Theoretically envisioned as driven by strong electronic correlations, the intertwined order is usually found to be strongly coupled to the lattice as signaled by pronounced phonon softening. Recently, both charge/spin density waves (CDW/SDW) and superconductivity have been discovered in several Ruddlesden-Popper (RP) nickelates, in particular trilayer nickelates RE4Ni3O10 (RE=Pr, La). The nature of the intertwined order and the role of lattice-charge coupling are at the heart of the debate about these materials. Using inelastic X-ray scattering, we mapped the phonon dispersions in RE4Ni3O10 and found no evidence of phonon softening near the CDW wavevector over a wide temperature range. Calculations of the electronic susceptibility revealed a peak at the observed SDW ordering vector but not at the CDW wavevector. The absence of phonon softening is in sharp contrast to that in canonical oxide materials, notably cuprates. Our experimental and theoretical findings highlight the crucial role of the spin degree of freedom and establish a foundation for understanding the interplay between superconductivity and density-wave transitions in RP nickelate superconductors and beyond.