Spin-orbit coupling and electronic correlations in Hund's metals: Sr₂RuO₄

We investigate the interplay of spin-orbit coupling (SOC) and Hund's rule coupling driven electronic correlations in Sr₂RuO₄ using dynamical mean-field theory. We find that the orbital-diagonal components of the dynamical electronic correlations are unaffected by the SOC, which validates the concept of a Hund’s metal in the presence of SOC. In contrast, SOC itself is enhanced by approximately a factor of two by electronic correlations. We introduce the concept of an energy-dependent quasiparticle SOC, which is found to be essential in accounting simultaneously for: (i) the Fermi surface (ii) the low-energy dispersion of quasiparticles and (iii) the splitting between bands at higher binding energy. Our calculations are in good agreement with available experimental data. References: [1-4]

[1] C. Veenstra et al., Physical Review Letters 112, 127002 (2014)
[2] M. Haverkort et al., Physical Review Letters 101, 026406 (2008)
[3] J. Mravlje et al., Physical Review Letters 106, 096401 (2011)
[4] M. Kim et al., arXiv preprint arXiv:1707.02462 (2017)