Investigating the Uranium Electronic Structure in Pristine UTe₂ via HERFD-XANES and RIXS: A Comparative Analysis with Other p-Ligand Systems

We propose to investigate the uranium chemical state in ultra-clean samples of the recently discovered unconventional superconductor UTe2 using high-energy resolution fluorescence detection X-ray absorption near edge spectroscopy (HERFD-XANES) and Resonant Inelastic X-ray Scattering (RIXS) at the uranium M₄ edge, comparing the results with UGe2 and previously measured UGa2. HERFD-XANES and RIXS have proven effective [1] in providing fingerprint information on the oxidation state, probing 5f occupancy, and offering detailed insights into mixed-valence states in actinide materials. We anticipate that applying this high-resolution spectroscopic technique to UX₂ compounds will yield crucial information on their electronic structure and enhance our understanding of how different p-block ligands influence the 5f electron configurations and consequently, the resulting materials’ properties.