标题： CaCu$_3$Ru$_4$O$_{12}$：一种高科恩多温度的过渡金属氧化物 显示英文标题

标题： CaCu$_3$Ru$_4$O$_{12}$: a high Kondo-temperature transition metal oxide

摘要： 我们使用体敏感的硬X射线和软X射线谱学结合局部密度近似(LDA)+动力平均场理论(DMFT)计算，对CaCu$_3$Ru$_4$O$_{12}$进行了全面研究。 Cu和Ru离子上的关联效应可以被观察到。 从Cu$2p$本征能级光谱中，我们推断出存在与巡游电子库杂化的磁性Cu$^{2+}$离子。 价带的强光子能量依赖性使我们能够分离Ru、Cu和O的贡献，从而优化DMFT计算。 计算得到的自旋和电荷磁化率表明，过渡金属氧化物 CaCu$_3$Ru$_4$O$_{12}$必须被归类为 Kondo 系统，且 Kondo 温度在 500-1000 K 范围内。 显示英文摘要

摘要： We present a comprehensive study of CaCu$_3$Ru$_4$O$_{12}$ using bulk sensitive hard and soft x-ray spectroscopy combined with local-density approximation (LDA) + dynamical mean-field theory (DMFT) calculations. Correlation effects on both the Cu and Ru ions can be observed. From the Cu $2p$ core level spectra we deduce the presence of magnetic Cu$^{2+}$ ions hybridized with a reservoir of itinerant electrons. The strong photon energy dependence of the valence band allows us to disentangle the Ru, Cu, and O contributions and thus to optimize the DMFT calculations. The calculated spin and charge susceptibilities show that the transition metal oxide CaCu$_3$Ru$_4$O$_{12}$ must be classified as a Kondo system and that the Kondo temperature is in the range of 500-1000 K.