Interplay between local electron correlation and Janh-Teller electron-phonon interaction

TL;DR

This paper investigates how strong local electron correlations interact with Jahn-Teller electron-phonon coupling in a model relevant to orbital physics, revealing that Jahn-Teller effects significantly suppress the Kondo temperature.

Contribution

It introduces a detailed analysis of the interplay between electron correlation and Jahn-Teller phonons using the large degeneracy expansion in the Anderson model.

Findings

Jahn-Teller interaction decreases the Kondo temperature.

Jahn-Teller effects strongly influence dynamical correlation functions.

Contrast with Holstein phonons shows different impact on charge vs. orbital degrees of freedom.

Abstract

The infinite-$U$ Anderson model coupled to a Jahn-Teller phonon is studied using the slave boson method on the basis of the large degeneracy expansion (1/N) scheme. The model Hamiltonian acts on the orbital degrees of freedom. The main focus is on the interplay between strong local electron correlation and weak Jahn-Teller electron-phonon interaction. The Kondo temperature is found to decrease by Jahn-Teller interaction. The influence of the Jahn-Teller interaction on dynamical correlation functions is very significant in sharp contrast with the case of the Holstein-type phonon which couples to charge degrees of freedom.