Identifying f-electron symmetries of UTe2 with O-edge resonant inelastic X-ray scattering
Abstract
The recent discovery of spin-triplet superconductivity emerging from a non-magnetic 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 an 5f26d1-like valence electron configuration with weak intra-dimer magnetic correlations, and provide new context for interpreting recent investigations of the electronic structure and superconducting pairing mechanism.