Signatures of Hund metal and finite-frequency nesting in Sr2RuO4 revealed by electronic Raman scattering

Abstract

We investigate the electronic Raman scattering of Sr2RuO4 using a material-realistic dynamical mean-field theory approach. We identify the low-energy Fermi liquid behavior and point out that the enhanced Raman response at higher energies is a fingerprint of Hund metals. These signatures originate in the two-stage coherence of Hund metals and associated quasiparticle “unrenormalization.” In agreement with recent experimental observations, we find the B1g and B2g responses differ, but our calculations suggest a novel interpretation of this dichotomy. The B1g response is dominated by the xy orbital and the B2g response receives contributions from all orbitals and is strongly affected by previously unnoticed finite-frequency interband nesting. We calculate the vertex-corrections to Raman response and show that their effect is nonvanishing but small. Published by the American Physical Society 2024