Lewin Sylvia K, Czajka Peter, Frank Corey E, Saucedo Salas Gicela, Noe Ii G Timothy, Yoon Hyeok, Eo Yun Suk, Paglione Johnpierre, Nevidomskyy Andriy H, Singleton John, Butch Nicholas P
NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA.
Maryland Quantum Materials Center, Department of Physics, University of Maryland, College Park, MD, USA.
Science. 2025 Jul 31;389(6759):512-515. doi: 10.1126/science.adn7673.
The heavy fermion material UTe 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 crystallographic plane and reveal its core structure: The superconducting phase wraps around the 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's specific magnetophilic superconducting tendencies seem incompatible with existing models for field-enhanced superconductivity.
