The coherence-incoherence crossover and the mass-renormalization puzzles in Sr2RuO4

TL;DR

This paper investigates the electronic structure of Sr2RuO4 using dynamical mean-field theory, revealing the origins of mass renormalization and incoherence crossover driven by Hund's coupling and orbital effects.

Contribution

It demonstrates how Hund's coupling and orbital differentiation explain key correlated phenomena in Sr2RuO4, with implications for other materials.

Findings

Reproduces experimental mass renormalization

Explains incoherence crossover at low temperature

Identifies Hund's coupling as a key driver

Abstract

We calculate the electronic structure of Sr2RuO4, treating correlations in the framework of dynamical mean-field theory. The approach successfully reproduces several experimental results and explains the key properties of this material: the anisotropic mass renormalization of quasiparticles and the crossover into an incoherent regime at a low temperature. While the orbital differentiation originates from the proximity of the van Hove singularity, strong correlations are caused by the Hund's coupling. The generality of this mechanism for other correlated materials is pointed out.