标题： 磁性增强的无限层镍氧化物中的强电子-声子耦合 显示英文标题

标题： Magnetism-Enhanced Strong Electron-Phonon Coupling in Infinite-Layer Nickelate

摘要： 镍酸盐和铜酸盐之间的有趣类比为揭示高温$T_c$超导性的微观机制提供了有前景的途径。 虽然镍酸盐中的电子关联效应已被广泛研究，但电子-声子耦合（EPC）的作用仍然存在很大争议。 在这里，以纯净的 LaNiO$_2$作为典型的镍酸盐，我们使用先进的密度泛函理论方法，对非磁性（NM）和$C$类型反铁磁（$C$-AFM）相的EPC进行了深入研究，而无需引入$U$或其他自由参数。 在NM相中的弱EPC强度$\lambda$被发现由于$C$-AFM相中磁性的存在而显著增强（$\sim$4$\times$）。这种增强是由于与Ni-3$d_{z^2}$轨道相关的平带与由Ni和La原子振动驱动的低频声子模式之间的强相互作用引起的。结果显示，声子软化会在约15 meV处产生电子结构中的明显台阶，这将为我们预测提供可实验验证的特征。我们的研究突显了局部磁矩和层间EPC在镍氧化物中的关键作用。 显示英文摘要

摘要： Intriguing analogies between the nickelates and the cuprates provide a promising avenue for unraveling the microscopic mechanisms underlying high-$T_c$ superconductivity. While electron correlation effects in the nickelates have been extensively studied, the role of electron-phonon coupling (EPC) remains highly controversial. Here, by taking pristine LaNiO$_2$ as an exemplar nickelate, we present an in-depth study of EPC for both the non-magnetic (NM) and the $C$-type antiferromagnetic ($C$-AFM) phase using advanced density functional theory methods without invoking $U$ or other free parameters. The weak EPC strength $\lambda$ in the NM phase is found to be greatly enhanced ($\sim$4$\times$) due to the presence of magnetism in the $C$-AFM phase. This enhancement arises from strong interactions between the flat bands associated with the Ni-3$d_{z^2}$ orbitals and the low-frequency phonon modes driven by the vibrations of Ni and La atoms. The resulting phonon softening is shown to yield a distinctive kink in the electronic structure around 15 meV, which would provide an experimentally testable signature of our predictions. Our study highlights the critical role of local magnetic moments and interply EPC in the nickelate.