Field-induced compensation of magnetic exchange as the possible origin of reentrant superconductivity in UTe<sub>2</sub>.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 38167667.
- Also identified by DOI 10.1038/s41467-023-44183-1 and PMC identifier 10761692.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The potential spin-triplet heavy-fermion superconductor UTe<sub>2</sub> exhibits signatures of multiple distinct superconducting phases. For field aligned along the b axis, a metamagnetic transition occurs at μ<sub>0</sub>H<sub>m</sub> ≈ 35 T. It is associated with magnetic fluctuations that may be beneficial for the field-reinforced superconductivity surviving up to H<sub>m</sub>. Once the field is tilted away from the b towards the c axis, a reentrant superconducting phase emerges just above H<sub>m</sub>. 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 of μ<sub>0</sub>H<sub>c2</sub> ≈ 73 T and its evolution with angle. Furthermore, the normal-state Hall effect experiences a drastic suppression indicative of a reduced band polarization above H<sub>m</sub> in 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 above H<sub>m</sub>.