Enhanced triplet superconductivity in next-generation ultraclean UTe2

• 成果类型: Article
• 署名作者: Wu, Z.; Weinberger, T. I.; Chen, J.; Cabala, A.; Chichinadze, D. V.; Shaffer, D.; Pospisil, J.; Prokleska, J.; Haidamak, T.; Bastien, G.; Sechovsky, V.; Hickey, A. J.; Mancera-Ugarte, M. J.; Benjamin, S.; Graf, D. E.; Skourski, Y.; Lonzarich, G. G.; Valiska, M.; Grosche, F. M.; Eaton, A. G.
• 署名单位: University of Cambridge; Charles University Prague; State University System of Florida; Florida State University; Emory University; University of Wisconsin System; University of Wisconsin Madison; University of Cambridge; Helmholtz Association; Helmholtz-Zentrum Dresden-Rossendorf (HZDR)
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8826
• DOI: 10.1073/pnas.2403067121
• 发表日期: 2024-09-10
• 关键词: critical field; ferromagnetism; maximum; state

摘要

The unconventional superconductor UTe2 exhibits numerous signatures of spin-triplet superconductivity-a rare state of matter which could enable quantum computation protected against decoherence. UTe2 possesses a complex phase landscape comprising two magnetic field-induced superconducting phases, a metamagnetic transition to a field-polarized state, along with pair- and charge-density wave orders. However, contradictory reports between studies performed on UTe2 specimens of varying quality have severely impeded theoretical efforts to understand the microscopic origins of the exotic superconductivity. Here, we report a comprehensive suite of high magnetic field measurements on a generation of pristine quality UTe2 crystals. Our experiments reveal a significantly revised high magnetic field superconducting phase diagram in the ultraclean limit, showing a pronounced sensitivity of field-induced superconductivity to the presence of crystalline disorder. We employ a Ginzburg-Landau model that excellently captures this acute dependence on sample quality. Our results suggest that in close proximity to a field-induced metamagnetic transition the enhanced role of magnetic fluctuations-that are strongly suppressed by disorder-is likely responsible for tuning UTe2 between two distinct spin-triplet superconducting phases.