Lawrence Berkeley National Laboratory

The recent discovery of spin-triplet superconductivity emerging from a nonmagnetic parent state in UTe2 has stimulated great interest in the underlying mechanism of Cooper pairing. Experimental characterization of short-range electronic and magnetic correlations is vital to understanding these phenomena. Here we use resonant inelastic x-ray scattering (RIXS), x-ray absorption spectroscopy (XAS), and atomic-multiplet-based modeling to shed light on the active debate between 5f26d1-based models with singlet crystal field states versus 5f3-based models that predict atomic Kramers doublets and much greater 5f itinerancy. The XAS and RIXS data are found to agree strongly with predictions for a 5f26d1-like valence electron configuration with weak intradimer magnetic correlations, and provide a context for interpreting recent investigations of the electronic structure and superconducting pairing mechanism.