Authors: Toni Helm, Motoi Kimata, Kenta Sudo, Atsuhiko Miyata, Julia Stirnat, Tobias Förster, Jacob Hornung, Markus König, Ilya Sheikin, Alexandre Pourret, Gerard Lapertot, Dai Aoki, Georg Knebel, Joachim Wosnitza, Jean-Pascal Brison
Published: 2024-01-02
DOI: 10.1038/s41467-023-44183-1
Source: Full article
AbstractThe potential spin-triplet heavy-fermion superconductor UTe2exhibits signatures of multiple distinct superconducting phases. For field aligned along thebaxis, a metamagnetic transition occurs atμ0Hm ≈ 35 T. It is associated with magnetic fluctuations that may be beneficial for the field-reinforced superconductivity surviving up toHm. Once the field is tilted away from thebtowards thecaxis, a reentrant superconducting phase emerges just aboveHm. In order to better understand this remarkably field-resistant superconducting phase, we conducted magnetic-torque and magnetotransport measurements in pulsed magnetic fields. We determine the record-breaking upper critical field ofμ0Hc2 ≈ 73 T and its evolution with angle. Furthermore, the normal-state Hall effect experiences a drastic suppression indicative of a reduced band polarization aboveHmin the angular range around 30° caused by a partial compensation between the applied field and an exchange field. This promotes the Jaccarino-Peter effect as a likely mechanism for the reentrant superconductivity aboveHm.