X-ray magnetic circular dichroism and resonant inelastic X-ray scattering explained: role of many-body correlation and valence fluctuations

Beom Hyun Kim; Sang-Jun Lee; H. Huang; D. Lu; S. S. Hong; S. Lee; P. Abbamonte; Y. I. Joe; P. Szypryt; W. B. Doriese; D. S. Swetz; J. N. Ullom; C. -C. Kao; J. -S. Lee; Bongjae Kim

arXiv · 2412.07204

X-ray magnetic circular dichroism and resonant inelastic X-ray scattering explained: role of many-body correlation and valence fluctuations

Beom Hyun Kim·Sang-Jun Lee·H. Huang·D. Lu·S. S. Hong·S. Lee·P. Abbamonte·Y. I. Joe·P. Szypryt·W. B. Doriese·D. S. Swetz·J. N. Ullom·C. -C. Kao·J. -S. Lee·Bongjae Kim

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Abstract

X-ray magnetic circular dichroism (XMCD) and resonant inelastic X-ray scattering with magnetic circular dichroism (RIXS-MCD) provide unparalleled insights into the electronic and magnetic dynamics of complex materials. However, interpreting their spectra in mixed-valence systems remains challenging due to intricate many-body interactions and enhanced charge fluctuations. In this study, by utilizing the Anderson impurity model with a full consideration of charge transfer (CT), many-body core-valence exchange correlation (CVEC) effects, and Jahn-Teller (JT) distortions, we systematically investigate the XMCD and RIXS-MCD spectra for a prototypical mixed-valence ferromagnet, La$_{0.7}$Sr$_{0.3}$MnO$_3$ film. We demonstrate that simple calculation with limited CT effects fails to capture characteristic substructures observed experimentally. In contrast, an adequate treatment of CT and CVEC effects yields a more consistent description of both XMCD and RIXS-MCD spectra, providing practical guidance for the interpretation of dichroic x-ray spectroscopies in mixed-valence transition-metal oxides. Furthermore, we discuss the role of the JT effect in Mn$^{3+}$ ions in the determination of their spectra.

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Beom Hyun Kim, Sang-Jun Lee, H. Huang, D. Lu, S. S. Hong, S. Lee, P. Abbamonte, Y. I. Joe, P. Szypryt, W. B. Doriese, D. S. Swetz, J. N. Ullom, C. -C. Kao, J. -S. Lee, Bongjae Kim. 2024-12-10. X-ray magnetic circular dichroism and resonant inelastic X-ray scattering explained: role of many-body correlation and valence fluctuations. https://arxiv.org/abs/2412.07204

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