Eur. Phys. J. B 45, 1-4 (2005)
https://doi.org/10.1140/epjb/e2005-00157-8

Sum rules for X-ray magnetic circular dichroism spectra in strongly correlated ferromagnets

¹ Institute of Metal Physics, 620219 Ekaterinburg, Russia
² Institute for Molecules and Materials, Radboud University, 6525 ED Nijmegen, The Netherlands

Corresponding author: ^a M.Katsnelson@science.ru.nl

Received: 7 March 2005
Published online: 16 June 2005

Abstract

It is proven that the sum rules for X-ray magnetic dichroism (XMCD) spectra that are used to separate spin and orbital contributions to the magnetic moment are formally correct for an arbitrary strength of electron-electron interactions. However, their practical application for strongly correlated systems can become complicated due to the spectral density weight spreading over a broad energy interval. Relevance of incoherent spectral density for the XMCD sum rules is illustrated by a simple model of a ferromagnet with orbital degrees of freedom.