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Evidence for strong electronic correlations in the spectra of Sr$_2$RuO$_4$

Z. V. Pchelkina·I. A. Nekrasov·Th. Pruschke·A. Sekiyama·S. Suga·V. I. Anisimov·D. Vollhardt
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Abstract

The importance of electronic correlation effects in the layered perovskite Sr$_2$RuO$_4$ is evidenced. To this end we use state-of-the-art LDA+DMFT (Local Density Approximation + Dynamical Mean-Field Theory) in the basis of Wannier functions to compute spectral functions and the quasiparticle dispersion of Sr$_2$RuO$_4$. The spectra are found to be in good agreement with various spectroscopic experiments. We also calculate the $\textbf{k}$-dependence of the quasiparticle bands and compare the results with new angle resolved photoemission (ARPES) data. Two typical manifestations of strong Coulomb correlations are revealed: (i) the calculated quasiparticle mass enhancement of $m^*/m \approx2.5$ agrees with various experimental results, and (ii) the satellite structure at about 3 eV binding energy observed in photoemission experiments is shown to be the lower Hubbard band. For these reasons Sr$_2$RuO$_4$ is identified as a strongly correlated 4$d$ electron material.

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Z. V. Pchelkina, I. A. Nekrasov, Th. Pruschke, A. Sekiyama, S. Suga, V. I. Anisimov, D. Vollhardt. 2006-01-23. Evidence for strong electronic correlations in the spectra of Sr$_2$RuO$_4$. https://doi.org/10.1103/physrevb.75.035122

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