Observation of odd-parity superconductivity in UTe2

• 成果类型: Article
• 署名作者: Li, Zixuan; Moir, Camilla M.; McKee, Nathan J.; Lee-Wong, Eric; Baumbach, Ryan E.; Maple, M. Brian; Liu, Ying
• 署名单位: Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; University of California System; University of California San Diego; University of California System; University of California San Diego; State University System of Florida; Florida State University; State University System of Florida; Florida State University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8748
• DOI: 10.1073/pnas.2419734122
• 发表日期: 2025-04-01
• 关键词: states

摘要

Symmetry properties of the order parameter are among the most fundamental characteristics of a superconductor. UTe2, which was found to feature an exceedingly large upper critical field and striking reentrant behavior at low temperatures, is widely believed to possess a spin-triplet pairing symmetry. However, unambiguous evidence for such a pairing symmetry is still lacking, especially at zero and low magnetic fields. The presence of an inversion crystalline symmetry in UTe2 requires that, if it is indeed a spin-triplet superconductor, the order parameter must be of odd parity. We report here phase-sensitive measurements of the symmetry of the orbital part of the order parameter using the Josephson effect. The selection rule in the orientation dependence of the Josephson coupling between In, an s-wave superconductor, and UTe2 suggests strongly that UTe2 possesses the odd-parity pairing state of B1u symmetry near zero magnetic field, making it a spin-triplet superconductor. We also report the apparent formation of Andreev surface bound states on the (1-10) surface of UTe2.