Resonant inelastic x-ray scattering spectra for electrons in solids

TLDR: In this paper, the Anderson impurity model and cluster model are used to model the effects of intra-atomic multiplet coupling and weak interatomic electron transfer. But the Anderson model is not suitable for the case of transition-metal compounds, where the 4f electrons are localized with strong electron correlation.

Abstract: conservation are discussed. At the opposite extreme are rare-earth systems (metals and oxides), in which the 4f electrons are almost localized with strong electron correlation. The observations are interpreted based on the effects of intra-atomic multiplet coupling and weak interatomic electron transfer, which are well described with an Anderson impurity model or a cluster model. In this context a narrowing of spectral width in the excitation spectrum, polarization dependence, and the magnetic circular dichroism in ferromagnetic materials are discussed. The authors then consider transition-metal compounds, materials with electron correlation strengths intermediate between semiconductors and rare-earth systems. In these interesting cases there is an interplay of intra-atomic and interatomic electronic interactions that leads to limitations of both the band model and the Anderson impurity model. Finally, other topics in resonant x-ray emission studies of solids are described briefly.