Electronic structure and effects of dynamical electron correlation in ferromagnetic bcc-Fe, fcc-Ni and antiferromagnetic NiO

TL;DR

This paper applies an advanced LDA+DMFT method to study the electronic structure of ferromagnetic bcc-Fe, fcc-Ni, and antiferromagnetic NiO, revealing the importance of dynamical correlations and configuration mixing in matching experimental data.

Contribution

It introduces a full LDA Hamiltonian-based LDA+DMFT approach without Wannier orbital mapping and demonstrates its effectiveness on transition metals and oxides.

Findings

Narrower 3d bands in Fe and Ni compared to LDA.

Appearance of Ni 6eV satellite in spectral data.

Band gap of 4.3 eV in NiO consistent with experiments.

Abstract

LDA+DMFT method in the framework of the iterative perturbation theory (IPT) with full LDA Hamiltonian without mapping onto the effective Wannier orbitals. We then apply this LDA+DMFT method to ferromagnetic bcc-Fe and fcc-Ni as a test of transition metal, and to antiferromagnetic NiO as an example of transition metal oxide. In Fe and Ni, the width of occupied 3d bands is narrower than those in LDA and Ni 6eV satellite appears. In NiO, the resultant electronic structure is of charge-transfer insulator type and the band gap is 4.3eV. These results are in good agreement with the experimental XPS. The configuration mixing and dynamical correlation effects play a crucial role in these results.