Hallmark features of conventional BCS superconductivity in 2H-TaS2
Artikel i vetenskaplig tidskrift, 2025
Layered transition metal dichalcogenides (TMDs) are model systems to investigate the interplay between superconductivity and the charge density wave (CDW) order. Here, we use muon spin rotation and relaxation (μ+SR) to probe the superconducting ground state of polycrystalline 2H-TaS2, which hosts a CDW transition at 76 K and superconductivity below 1 K. The μ+SR measurements, conducted down to 0.27 K, are consistent with a nodeless, BCS-like single-gap s-wave state. Fits to the temperature dependence of the depolarization rate and Knight shift measurements support spin-singlet pairing. Crucially, no evidence of time-reversal symmetry breaking (TRSB) is observed, distinguishing 2H-TaS2 from polymorphs like 4Hb-TaS2, where TRSB and unconventional superconductivity have been reported. These findings establish 2H-TaS2 as a canonical BCS superconductor and provide a reference point for understanding the diverse electronic ground states that emerge in structurally distinct TMD polymorphs.
Muon spin rotation μ+SR
Superconductivity
Van der Waals
Författare
Frank Elson
Kungliga Tekniska Högskolan (KTH)
Ola Kenji Forslund
Universität Zürich
Uppsala universitet
Rasmus Palm
Tartu Ülikool
Kungliga Tekniska Högskolan (KTH)
Ahmed Alshemi
Lunds universitet
Mahmoud Abdel-Hafiez
University of Sharjah
Gediminas Simutis
Paul Scherrer Institut
T. Shiroka
Paul Scherrer Institut
Eidgenössische Technische Hochschule Zürich (ETH)
D. Das
Paul Scherrer Institut
Elizabeth Blackburn
Lunds universitet
Jonas Weissenrieder
Kungliga Tekniska Högskolan (KTH)
Yasmine Sassa
Kungliga Tekniska Högskolan (KTH)
Chalmers, Fysik, Materialfysik
Martin Månsson
Kungliga Tekniska Högskolan (KTH)
Scientific Reports
2045-2322 (ISSN) 20452322 (eISSN)
Vol. 15 1 37164Ämneskategorier (SSIF 2025)
Den kondenserade materiens fysik
DOI
10.1038/s41598-025-24342-8