Theory Meets Experiment in Low-Dimensional Structures with Correlated Electrons

We develop an ab-initio computational method for analyzing modern resonant inelastic x-ray scattering (RIXS) spectra in correlated materials, such as 3d transition-metal and 4f rare-earth compounds. The method builds on the combination of local density approximation (LDA) and dynamical mean-field theory (DMFT), and can describe fine RIXS features originating from both localized (e.g. multiplet excitations) and delocalized excitations (e.g. charge-transfer, unbound electron-hole pair excitations) [1]. In this talk, we present calculated L-edge RIXS spectra for typical 3d transition-metal oxides: NiO, Fe₂O₃, LaMnO₃ and RNiO₃ with a comparison to high-resolution experimental data. We discuss the relation of the emergent charge excitations in RIXS spectra and low-energy valence states. Special attention will be paid on the coexistence/interference between the localized and delocalized excitations in the RIXS spectra, observed in recent experiments [2].

[1] A. Hariki et al., Phys. Rev. Lett. 121, 126403 (2018).

[2] V. Bisogni et al., Nat. Commun. 7, 13017 (2016).