Renormalized Perturbation Approach for Examination of Itinerant-Localized Duality Model for Strongly Correlated Electron Systems

TL;DR

This paper develops a microscopic approach to analyze the itinerant-localized duality model in strongly correlated electron systems, revealing the role of triple-peak spectral structures and superexchange interactions.

Contribution

It introduces a renormalized perturbation framework to validate the duality model and elucidates the interactions among localized spins in such systems.

Findings

Thermodynamic potential can be expressed via duality model with triple-peak spectral weight.

Existence of superexchange interactions among localized spins.

Incoherent degrees of freedom are characterized as localized spins.

Abstract

We present a microscopic examination for the itinerant-localized duality model which has been proposed to understand anomalous properties of strongly correlated systems like the heavy fermions by Kuramoto and Miyake, and also useful to describe the anomalous properties of the high-Tc cupurates. We show that the thermodynamic potential of the strongly interacting Hubbard model can be rearranged in the form of duality model on the basis of renormalized perturbation expansion of the Luttinger-Ward functional if the one-particle spectral weight exhibits triple peak structure. We also examine the incoherent degrees of freedom described as a ``localized spin'' and show on the basis of the pertubation expansion that there exists commensurate superexchange-type interaction among the ``localized spins''.