Local Moments in an Interacting Environment

TL;DR

This paper explores how interactions in the conduction sea alter local moment physics, revealing new symmetry channels and significant effects near the Mott transition, with implications for models like Zhang-Rice reduction.

Contribution

It introduces a detailed analysis of how conduction electron interactions modify local moment behavior, especially near the Mott transition, using a Schrieffer Wolff transformation.

Findings

Interactions open new symmetry channels for spin exchange.

Corrections become severe near the Mott transition.

Modifications to Zhang-Rice reduction are demonstrated.

Abstract

We discuss how local moment physics is modified by the presence of interactions in the conduction sea. Interactions in the conduction sea are shown to open up new symmetry channels for the exchange of spin with the localized moment. We illustrate this conclusion in the strong-coupling limit by carrying out a Schrieffer Wolff transformation for a local moment in an interacting electron sea, and show that these corrections become very severe in the approach to a Mott transition. As an example, we show how the Zhang Rice reduction of a two-band model is modified by these new effects.