Electronic Structure of UTe${}_2$ Studied by Photoelectron Spectroscopy

The electronic structure of the unconventional superconductor UTe${}_2$ was studied by resonant photoelectron spectroscopy (RPES) and angle-resolved photoelectron spectroscopy (ARPES) with soft X-ray synchrotron radiation. The partial $\mathrm{U}5f$ density of states of UTe${}_2$ were imaged by the $\mathrm{U}4d$–$5f$ RPES and it was found that the $\mathrm{U}5f$ state has an itinerant character, but there exists an incoherent peak due to the strong electron correlation effects. Furthermore, an anomalous admixture of the $\mathrm{U}5f$ states into the $\mathrm{T}\mathrm{e}5p$ bands was observed at a higher binding energy, which cannot be explained by band structure calculations. On the other hand, the band structure of UTe${}_2$ was obtained by ARPES and its overall band structure were mostly explained by band structure calculations. These results suggest that the $\mathrm{U}5f$ states of UTe${}_2$ have itinerant but strongly-correlated nature with enhanced hybridization with the $\mathrm{T}\mathrm{e}5p$ states.