Electronic Origin of the Volume Collapse in Cerium

TL;DR

This study uses advanced many-body wave functions to explain the electronic origin of cerium's volume collapse transition, revealing a complex electronic rearrangement involving p-f hybridization.

Contribution

It introduces a non-perturbative variational approach that accurately reproduces cerium's phase transition and links it to electronic structure changes, especially p-f hybridization.

Findings

First-order phase transition at T=0K confirmed

Electronic structure rearrangement involving p-f hybridization identified

Method accurately reproduces experimental structural properties

Abstract

The cerium alpha-gamma phase transition is characterized by means of a many-body Jastrow-correlated wave function, which minimizes the variational energy of the first-principles scalar-relativistic Hamiltonian, and includes correlation effects in a non-perturbative way. Our variational ansatz accurately reproduces the structural properties of the two phases, and proves that even at temperature $T=0$K the system undergoes a first order transition, with ab initio parameters which are seamlessly connected to the ones measured by experiment at finite $T$. We show that the transition is related to a complex rearrangement of the electronic structure, with key role played by the p-f hybridization. The underlying mechanism unveiled by this work can hold in many Ce-bearing compounds, and more generally in other f-electron systems.