Abstract and subjects
We investigate the topological superconductor candidate UTe2 using high-resolution valence-band resonant inelastic x-ray scattering at the U M-4,M-5 edges. We observe atomiclike low-energy excitations that support the correlated nature of this unconventional superconductor. These excitations originate from the U 5 f(2) configuration, which is unexpected since the short Te2-Te2 distances exclude Te2 being 2-. By utilizing the photoionization cross-section dependence of the photoemission spectra in combination with band structure calculations, we infer that the stabilization of the U 5 f(2) configuration is due to the U 6d bonding states in the U dimers acting as a charge reservoir. Our results emphasize that the description of the physical properties should commence with a 5 f(2) ansatz.