High-resolution photoemission on Sr2RuO4 reveals correlation-enhanced effective spin-orbit coupling and dominantly local self-energies
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We explore the interplay of electron-electron correlations and spin-orbit coupling in the model Fermi liquid Sr2RuO4 using laser-based angle-resolved photoemission spectroscopy. Our precise measurement of the Fermi surface confirms the importance of spin-orbit coupling in this material and reveals that its effective value is enhanced by a factor of about 2, due to electronic correlations. The self-energies for the β and γ sheets are found to display significant angular dependence. By taking into account the multi-orbital composition of quasiparticle states, we determine self-energies associated with each orbital component directly from the experimental data. This analysis demonstrates that the perceived angular dependence does not imply momentum-dependent many-body effects but arises from a substantial orbital mixing induced by spin-orbit coupling. A comparison to single-site dynamical mean-field theory further supports the notion of dominantly local orbital self-energies and provides strong evidence for an electronic origin of the observed nonlinear frequency dependence of the self-energies, leading to “kinks” in the quasiparticle dispersion of Sr2RuO4.
Tamai , A , Zingl , M , Rozbicki , E J , Cappelli , E , Riccò , S , de la Torre , A , McKeown-Walker , S , Bruno , F Y , King , P D , Meevasana , W , Shi , M , Radović , M , Plumb , N C , Gibbs , A S , Mackenzie , A P , Berthod , C , Strand , H U R , Kim , M , Georges , A & Baumberger , F 2019 , ' High-resolution photoemission on Sr 2 RuO 4 reveals correlation-enhanced effective spin-orbit coupling and dominantly local self-energies ' , Physical Review X , vol. 9 , no. 2 , 021048 . https://doi.org/10.1103/PhysRevX.9.021048
Physical Review X
Copyright the Author(s) 2019. Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.
DescriptionFunding: The experimental work has been supported by the European Research Council (ERC), the Scottish Funding Council, the UK EPSRC and the Swiss National Science Foundation (SNSF). Theoretical work was supported by the ERC grant ERC-319286-QMAC and by the SNSF (NCCR MARVEL).
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