RIXS study of spin excitation and charge order in the bulk phase of infinite-layer nickelates

Infinite-layer (IL) nickelates are a new class of superconductors that exhibits both similarities and differences to cuprates. Earlier resonant inelastic x-ray scattering (RIXS) studies on thin-film IL nickelates reported spin excitations and charge ordering patterns reminiscent of those in cuprates [1]. However, recent electron microsopy investigations on thin films identified topotactic impurity phases [2], potentially accounting for the emergence of the observed phenomena. To provide a complementary sample type, we have synthesized bulk crystals of the IL nickelate LaNiO₂ [3], and carried out RIXS experiments. In this talk, we will discuss the results of these experiments, clarifying the intrinsic spin and charge characteristics of the bulk phase of IL nickelates.