Spin-Orbit Coupling and Electronic Correlations in Sr2RuO4

TL;DR

This paper explores how spin-orbit coupling influences electronic correlations in Sr2RuO4, revealing that SOC alters the electronic structure without affecting correlation-induced renormalizations, and introduces the concept of energy-dependent quasiparticle SOC.

Contribution

It demonstrates that SOC does not impact correlation-driven renormalizations in Sr2RuO4 and introduces the energy-dependent quasiparticle spin-orbit coupling concept.

Findings

SOC does not affect correlation-induced renormalizations

SOC significantly changes electronic structure at degenerate k-points

Introduction of energy-dependent quasiparticle spin-orbit coupling

Abstract

We investigate the interplay of spin-orbit coupling (SOC) and electronic correlations in Sr2RuO4 using dynamical mean-field theory. We find that SOC does not affect the correlation-induced renormalizations, which validates the Hund's metal picture of ruthenates even in the presence of the sizable SOC relevant to these materials. Nonetheless, SOC found to change significantly the electronic structure at k-points where a degeneracy applies in its absence. We explain why these two observations are consistent with one another and calculate effects of SOC on the correlated electronic structure. The magnitude of these effects is found to depend on the energy of the quasiparticle state under consideration, leading us to introduce the notion of an "energy-dependent quasiparticle spin-orbit coupling". This notion is generally applicable to all materials in which both the spin-orbit coupling and electronic correlations are sizable.