Superconductivity in the high-pressure tetragonal phase of UTe(2).

Superconductivity in tetragonal UTe2 emerges near 5 GPa, peaks at ~4 K at 6 GPa, and vanishes near 18 GPa, indicating a pressure-dependent phase transition.

• Why it matters: Understanding the nature of superconductivity in UTe2 under pressure is crucial because it reveals the relationship between crystal structure and unconventional versus conventional pairing mechanisms, impacting theories of spin-triplet superconductivity.
• What they did: The study conducted electrical transport and magnetic measurements on UTe2 up to 16 GPa, mapping the T c vs. P phase diagram and analyzing critical fields and coherence length in the tetragonal phase.
• The result: The tetragonal phase exhibits a small upper critical field (~1.2 T at 5.3 GPa), favoring conventional superconductivity, contrasting with the orthorhombic phase's large H c2(T), which supports unconventional, spin-triplet pairing.