Electronic structure of the parent compound of superconducting infinite-layer nickelates*

Very recently, the first superconducting nickelate has been discovered, opening a new field of research. The novel superconductor is a Sr-doped infinite layer nickelate NdNiO₂, which is isostructural to the infinite-layer cuprates and possesses the same nominal 3d electron count. Yet, it is important to experimentally characterize the electronic state of the parent compound from which the superconductivity emerges. In this presentation, we will present data of soft x-ray spectroscopy (XAS and RIXS) near the Ni L-edge and O K-edge on parent compound RNiO₂ (R = La, Nd). Together with LDA + U calculations, the gross feature of the electronic structure and a low energy effective model for the infinite layer nickelate will be discussed.