Core-Level X-Ray Spectroscopy of Infinite-Layer Nickelate: LDA+DMFT Study

Abstract

Motivated by recent core-level x-ray photoemission spectroscopy, x-ray absorption spectroscopy (XAS), and resonant inelastic x-ray scattering (RIXS) experiments for the newly discovered superconducting infinite-layer nickelate, we investigate the core-level spectra of the parent compounds NdNiO_{2} and LaNiO_{2} using the combination of local density approximation and dynamical mean-field theory (LDA+DMFT). Adjusting a charge-transfer energy to match the experimental spectra, we determine the optimal model parameters and discuss the nature of the NdNiO_{2} ground state. We find that self-doping from the Nd 5d states in the vicinity of the Fermi energy prohibits opening of a Mott-Hubbard gap in NdNiO_{2}. The present Ni L_{3} XAS and RIXS calculation for LaNiO_{2} cannot explain the difference from NdNiO_{2} spectra.