Pressure induced valence and metal-insulator transitions in the Falicov-Kimball model with nonlocal hybridization

TL;DR

This paper introduces a realistic model based on the extended Falicov-Kimball framework to describe pressure-induced valence and metal-insulator transitions in mixed valence systems, aligning with experimental observations.

Contribution

It proposes a model linking external pressure to nonlocal hybridization, successfully capturing pressure-driven transitions in rare-earth compounds.

Findings

Model qualitatively reproduces experimental pressure-induced transitions.

Highlights the role of nonlocal hybridization in valence changes.

Provides insights into metal-insulator transition mechanisms.

Abstract

We present a simple, but very realistic, model for a description of pressure induced valence and metal-insulator transitions in mixed valence systems. It is based on the extended Falicov-Kimball model and the supposition that the key interaction governing these transitions is the nonlocal hybridization between the localized $f$ and itinerant $d$ electrons. Taking into account, in addition, the~parametrization between the external pressure and the $d$-$f$ hybridization (the experimental fact), the model is able to describe, at least qualitatively, valence as well as metal-insulator transitions driven by the external pressure observed experimentally in some rare-earth systems, like SmB$_6$.