Electronic Correlation and Magnetism in the Ferromagnetic Metal Fe3GeTe2

TL;DR

This study combines theoretical calculations and experimental measurements to demonstrate that electronic correlations significantly influence the magnetic properties and spectral features of Fe3GeTe2, a ferromagnetic metal.

Contribution

The paper introduces a combined LDA and DMFT approach to accurately describe electronic correlations in Fe3GeTe2, aligning theoretical predictions with experimental observations.

Findings

Enhanced Sommerfeld coefficient explained by LDA+DMFT

Magnetic moments match experimental data with correlations included

Spectral density agrees better with photoemission measurements

Abstract

Motivated by the search for design principles of rare-earth-free strong magnets, we present a study of electronic structure and magnetic properties of the ferromagnetic metal Fe3GeTe2 within local density approximation (LDA) of the density functional theory, and its combination with dynamical mean-field theory (DMFT). For comparison to these calculations, we have measured magnetic and thermodynamic properties as well as X-ray magnetic circular dichroism and the photoemission spectrum of single crystal Fe3GeTe2. We find that the experimentally determined Sommerfeld coefficient is enhanced by an order of magnitude with respect to the LDA value. This enhancement can be partially explained by LDA+DMFT. In addition, the inclusion of dynamical electronic correlation effects provides the experimentally observed magnetic moments, and the spectral density is in better agreement with photoemission data. These results establish the importance of electronic correlations in this ferromagnet.