High-field superconducting halo in UTe 2
- Sylvia K. Lewin
- Peter Czajka
- Corey E. Frank
- Gicela Saucedo Salas
- G. Timothy Noe II
- Hyeok Yoon
- Yun Suk Eo
- Johnpierre Paglione
- Andriy H. Nevidomskyy
- John Singleton
- Nicholas P. Butch
2025-07-31
The heavy fermion material UTe 2 is a candidate topological superconductor that exhibits multiple magnetic field–induced superconducting phases. One such phase exists only at fields greater than 40 tesla, a considerable scale given its critical temperature of only 2 K. Here, we extend measurements of this state with fields outside of the bc crystallographic plane and reveal its core structure: The superconducting phase wraps around the b axis in a halo-like fashion and appears to be stabilized by a field component perpendicular to the magnetic easy axis. This angle dependence points to a multicomponent spin-triplet order parameter with a finite angular momentum of the Cooper pairs. The pairing mechanism remains enigmatic, and UTe 2 ’s specific magnetophilic superconducting tendencies seem incompatible with existing models for field-enhanced superconductivity.