Theoretical study of resonant inelastic x-ray scattering spectra of nickelates

Nickelates have become an important system to explore with the recent discovery of superconductivity in the infinite layer system. Here, we study and explore the multi-orbital Hubbard-Kanamori model that was recently reported in [Phys Rev X 12 011055 (2022)] and is relevant for nickelates. We evaluate the resonant inelastic x-ray scattering (RIXS) response for this model and explore the sensitivities of different parameters within the model. In this work, we reveal the signatures of tetragonal distortions in the RIXS spectra at the oxygen K-edge of nickelates. We further report the low-energy excitations in RIXS spectra sensitivity to Hund's coupling and its implications on the ground state of the system. Our work, therefore, shows that the low-energy excitations in the RIXS spectra, if further resolved, can put strong constraints on the model and highlight the relevant degrees of freedom in the nickelates.