Spin freezing transition and non-Fermi-liquid self-energy in a 3-orbital model

TL;DR

This study uses dynamical mean field theory to explore a three-band model revealing a spin freezing transition and non-Fermi-liquid behavior, with implications for understanding optical conductivity in SrRuO_3.

Contribution

It identifies a quantum phase transition with a .5 power law self-energy in a three-orbital model, advancing understanding of spin freezing and non-Fermi-liquid states.

Findings

Discovery of a spin freezing transition between metallic phases.

Identification of a .5 power law self-energy at the critical line.

Relevance to optical conductivity behavior in SrRuO_3.

Abstract

A single-site dynamical mean field study of a three band model with the rotationally invariant interactions appropriate to the t_2g levels of a transition metal oxide reveals a quantum phase transition between a paramagnetic metallic phase and an incoherent metallic phase with frozen moments. The Mott transitions occurring at electron densities n=2,3 per site take place inside the frozen moment phase. The critical line separating the two phases is characterized by a self energy with the frequency dependence \Sigma(\omega)\sim \sqrt{\omega} and a broad quantum critical regime. The findings are discussed in the context of the power law observed in the optical conductivity of SrRuO_3.