Abstract
We study the low-energy surface electronic structure of the transition-metal dichalcogenide superconductor by spin- and angle-resolved photoemission, scanning tunneling microscopy, and density-functional theory-based supercell calculations. Comparing with its sister compound , we demonstrate how enhanced interlayer hopping in the Te-based material drives a band inversion within the antibonding -orbital manifold well above the Fermi level. We show how this mediates spin-polarized topological surface states which form rich multivalley Fermi surfaces with complex spin textures. Scanning tunneling spectroscopy reveals type-II superconductivity at the surface, and moreover shows no evidence for an unconventional component of its superconducting order parameter, despite the presence of topological surface states.
- Received 14 November 2017
- Revised 17 January 2018
DOI:https://doi.org/10.1103/PhysRevLett.120.156401
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