On-site correlation in valence and core states of ferromagnetic nickel

TL;DR

This paper introduces a method to incorporate narrow-band correlation effects into the electronic structure calculations of ferromagnetic nickel, achieving results that closely match experimental photoemission data.

Contribution

It presents a novel approach combining ab-initio band calculations with a three-body scattering solution to include correlation effects in valence and core states.

Findings

Spectral functions agree with photoemission data

Accurate band width and exchange splitting

Correct satellite energy positions

Abstract

We present a method which allows to include narrow-band correlation effects into the description of both valence and core states and we apply it to the prototypical case of nickel. The results of an ab-initio band calculation are used as input mean-field eigenstates for the calculation of self-energy corrections and spectral functions according to a three-body scattering solution of a multi-orbital Hubbard hamiltonian. The calculated quasi-particle spectra show a remarkable agreement with photoemission data in terms of band width, exchange splitting, satellite energy position of valence states, spin polarization of both the main line and the satellite of the 3p core level.