Atomic correlations in itinerant ferromagnets: quasi-particle bands of nickel

TL;DR

This study uses angle-resolved photoelectron spectroscopy and Gutzwiller theory to accurately measure and explain the band structure of nickel, highlighting the role of atomic correlations in its itinerant ferromagnetism.

Contribution

It introduces a nine-band Hubbard model with parameters derived from DFT that resolves previous discrepancies between experiment and theory for nickel.

Findings

Gutzwiller theory accurately reproduces nickel's band structure

Atomic correlations are key to understanding itinerant ferromagnetism

Experimental and theoretical results are in improved agreement

Abstract

We measure the band structure of nickel along various high-symmetry lines of the bulk Brillouin zone with angle-resolved photoelectron spectroscopy. The Gutzwiller theory for a nine-band Hubbard model whose tight-binding parameters are obtained from non-magnetic density-functional theory resolves most of the long-standing discrepancies between experiment and theory on nickel. Thereby we support the view of itinerant ferromagnetism as induced by atomic correlations.