Electronic Structure of Lanthanum Hydrides with Switchable Optical Properties

TL;DR

This paper investigates the electronic structure of lanthanum hydrides, revealing how electron correlation and localized states influence their switchable optical properties and metal-insulator transition.

Contribution

It provides a local model explanation for the optical changes and the metal-insulator transition in lanthanum hydrides, emphasizing electron correlation effects.

Findings

Electron correlation is crucial for understanding optical properties.

Metal-insulator transition occurs at x~0.8 in LaH_{2+x}.

Localized states at H-vacancies drive the transition.

Abstract

Recent dramatic changes in the optical properties of LaH_{2+x} and YH_{2+x} films discovered by Huiberts et al. suggest their electronic structure is described best by a local model. Electron correlation is important in H^- -centers and in explaining the transparent insulating behavior of LaH_3. The metal-insulator transition at $x\sim 0.8$ takes place in a band of highly localized states centered on the $H$-vacancies in the LaH_3 structure.