Stabilization of U $5f^2$ configuration in ${\mathrm{UTe}}_2$ through U $6d$ dimers in the presence of Te2 chains

Journal Article · 16 September 2024 · Physical Review Research

DOI: https://doi.org/10.1103/PhysRevResearch.6.033299 · OSTI ID:2474004

Christovam, Denise S. ; Sundermann, Martin ; Marino, Andrea; Takegami, Daisuke ; Falke, Johannes ; Dolmantas, Paulius; Harder, Manuel; Gretarsson, Hlynur ; Keimer, Bernhard; Gloskovskii, Andrei ; Haverkort, Maurits W.; Elfimov, Ilya; Zwicknagl, Gertrud; Andreev, Alexander V.; Havela, Ladislav ; Bordelon, Mitchell M.; Bauer, Eric D. ; Rosa, Priscila F. S. ; Severing, Andrea ; Tjeng, Liu Hao

We investigate the topological superconductor candidate ${\mathrm{UTe}}_2$ using high-resolution valence-band resonant inelastic x-ray scattering at the U  $M_{4,5}$ edges. We observe atomiclike low-energy excitations that support the correlated nature of this unconventional superconductor. These excitations originate from the U  $5f^2$ 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  $5f^2$ 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 $5f^2$ ansatz. Published by the American Physical Society 2024

• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES)
• OSTI ID: 2474004
• Journal Information: Physical Review Research, Journal Name: Physical Review Research Journal Issue: 3 Vol. 6; ISSN PPRHAI; ISSN 2643-1564
• Publisher: American Physical SocietyCopyright Statement
• Country of Publication: United States
• Language: English