1. CaCu$_3$Ru$_4$O$_{12}$: a high Kondo-temperature transition metal oxide
- Author
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Takegami, D., Kuo, C. Y., Kasebayashi, K., Kim, J. -G., Chang, C. F., Liu, C. E., Wu, C. N., Kasinathan, D., Altendorf, S. G., Hoefer, K., Meneghin, F., Marino, A., Liao, Y. F., Tsuei, K. D., Chen, C. T., Ko, K. -T., Günther, A., Ebbinghaus, S. G., Seo, J. W., Lee, D. H., Ryu, G., Komarek, A. C., Sugano, S., Shimakawa, Y., Tanaka, A., Mizokawa, T., Kuneš, J., Tjeng, L. H., and Hariki, A.
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Condensed Matter - Strongly Correlated Electrons - Abstract
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., Comment: Accepted for publication in Phys. Rev. X
- Published
- 2021
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