Terbium under High Pressure: First-Principles Dynamical Mean-Field Theory Study

TL;DR

This study uses advanced first-principles methods to explore how pressure affects the electronic structure and magnetic properties of terbium, revealing strong correlation effects and magnetic transitions consistent with experimental observations.

Contribution

It demonstrates the application of fully charge self-consistent DFT+DMFT to model pressure-induced electronic and magnetic changes in terbium, a heavy lanthanide, with results aligning with experiments.

Findings

Strong band renormalization due to correlations

Persistence of correlated electronic structures under pressure

Magnetic transition from ferromagnetism to paramagnetism at high temperature

Abstract

Elemental rare-earth metals provide a playground for studying novel electron correlation effects and complex magnetism. However, ab initio simulations of these systems remain challenging. Here, we employ fully charge self-consistent density functional theory and dynamical mean-field theory (DFT+DMFT) to investigate terbium (Tb) metal under pressure. We show that Tb exhibits a strong band renormalization due to correlation effects, with the calculated electron density of states in good agreement with the experiments. At higher pressures, the correlated electronic structures persist but with modulation in the Hubbard gap, highlighting the tunability of effective Coulomb interactions and kinetic energies. Our DFT+DMFT calculations further indicate a ferromagnetic ground state of Tb at low pressure and low temperature, as well as a transition from ferromagnetism to paramagnetism at elevated temperatures. These ab initio results also align with the experiments. Our study paves the way for exploring heavy lanthanides via advanced first-principles simulations.