Probing enhanced superconductivity in van der Waals polytypes of VxTaS2
Journal article, 2024
Layered transition metal dichalcogenides (TMDs) stabilize in multiple structural forms with profoundly distinct and exotic electronic phases. Interfacing different layer types is a promising route to manipulate TMDs' properties, not only as a means to engineer quantum devices but also as a route to explore fundamental physics in complex matter. Here we use angle-resolved photoemission (ARPES) to investigate a strong layering-dependent enhancement of superconductivity in TaS2, in which the superconducting transition temperature, T c , of its 2H structural phase is nearly tripled when insulating 1T layers are inserted into the system. The study is facilitated by a vanadium-intercalation approach to synthesizing various TaS2 polytypes, which improves the quality of the ARPES data while leaving key aspects of the electronic structure and properties intact. The spectra show the clear opening of the charge density wave gap in the pure 2H phase and its suppression when 1T layers are introduced to the system. Moreover, in the mixed-layer 4Hb system, we observe a strongly momentum-anisotropic increase in electron-phonon coupling near the Fermi level relative to the 2H phase. Both phenomena help to account for the increased Tc in mixed 2H/1T layer structures.
Author
Wojciech R. Pudelko
University of Zürich
Paul Scherrer Institut
Huanlong Liu
University of Zürich
Francesco Petocchi
University of Geneva
University of Fribourg
Hang Li
Paul Scherrer Institut
Eduardo Bonini Guedes
Paul Scherrer Institut
Julia Kuspert
University of Zürich
Karin von Arx
Chalmers, Physics, Materials Physics
Qisi Wang
University of Zürich
Chinese University of Hong Kong
Ron Cohn Wagner
University of Zürich
Craig M. Polley
Lund University
Mats Leandersson
Lund University
Jacek Osiecki
Lund University
Balasubramanian Thiagarajan
Lund University
Milan Radovic
Paul Scherrer Institut
Philipp Werner
University of Fribourg
Andreas Schilling
University of Zürich
Johan Chang
University of Zürich
N. C. Plumb
Paul Scherrer Institut
PHYSICAL REVIEW MATERIALS
2475-9953 (ISSN)
Vol. 8 10 104802Subject Categories
Condensed Matter Physics
DOI
10.1103/PhysRevMaterials.8.104802