Periodic Anderson model with electron-phonon correlated conduction band

TL;DR

This study uses dynamical mean field calculations to explore a periodic Anderson model with electron-phonon coupling, revealing a complex phase diagram with phase coexistence and polaronic effects relevant to Ce's $ ext{γ}$-$ ext{α}$ transition.

Contribution

It introduces a novel model incorporating electron-phonon interactions into the periodic Anderson framework, uncovering new phase transitions and polaronic phenomena.

Findings

First order phase transition with coexisting phases

Presence of Kondo and local moment states

Pronounced polaronic and bipolaronic properties

Abstract

This paper reports dynamical mean field calculations for the periodic Anderson model in which the conduction band is coupled to phonons. Motivated in part by recent attention to the role of phonons in the $\gamma$-$\alpha$ transition in Ce, this model yields a rich and unexpected phase diagram which is of intrinsic interest. Specifically, above a critical value of the electron-phonon interaction, a first order transition with two coexisting phases develops in the temperature-hybridization plane, which terminates at a second order critical point. The coexisting phases display the familiar Kondo screened and local moment character, yet they also exhibit pronounced polaronic and bipolaronic properties, respectively.