Sum rules for X-ray magnetic circular dichroism spectra in strongly correlated ferromagnets
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
Published online: 16 June 2005
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.
PACS: 78.70.Dm – X-ray absorption spectra / 78.70.En – X-ray emission spectra and fluorescence / 75.30.Mb – Valence fluctuation, Kondo lattice, and heavy-fermion phenomena / 71.28.+d – Narrow-band systems; intermediate-valence solids
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2005