Lifshitz-enhanced superfluid density in two-gap superconducting TiSe2
Artikel i vetenskaplig tidskrift, 2026
Superconductivity in TiSe2 emerges when the charge density wave (CDW) order is suppressed under pressure or doping. Recent theoretical and experimental studies suggest that a Lifshitz transition plays a key role in stabilizing the superconducting phase. Here, we present muon spin resonance measurements of pressurized TiSe2 , revealing a two-gap superconducting state. Our results indicate that the smaller gap contributes unexpectedly strongly to the total superfluid density. This effect is consistent with an enhanced density of states in a newly formed Fermi surface pocket at the Lifshitz transition. These findings provide microscopic insight into the interplay between CDW suppression, Fermi surface reconstruction, and multi-gap superconductivity in TiSe2 , demonstrating how pressure-induced changes in electronic structure can shape superconducting properties in layered materials.
Författare
Frank Elson
Kungliga Tekniska Högskolan (KTH)
J. Philippe
Universität Zürich
Paul Scherrer Institut
Gediminas Simutis
Paul Scherrer Institut
Ola Kenji Forslund
Uppsala universitet
Universität Zürich
Chalmers, Fysik, Materialfysik
Mahmoud Abdel-Hafiez
University of Sharjah
Marc Janoschek
Universität Zürich
Paul Scherrer Institut
Rustem Khasanov
Paul Scherrer Institut
D. Das
Paul Scherrer Institut
Jonas Weissenrieder
Kungliga Tekniska Högskolan (KTH)
D. W. Tam
Kungliga Tekniska Högskolan (KTH)
Yasmine Sassa
Kungliga Tekniska Högskolan (KTH)
Martin Månsson
Kungliga Tekniska Högskolan (KTH)
npj Quantum Materials
23974648 (eISSN)
Vol. 11 1 4Ämneskategorier (SSIF 2025)
Den kondenserade materiens fysik
DOI
10.1038/s41535-025-00834-8