2026/08/01 by Niclas Tilgner, Andres David Peña Unigarro, Susanne Wolff +6
Physics and Astronomy · #cond-mat.mtrl-sci
arxiv created 2026/08/01 · arxiv updated 2026/08/04
Recent studies have revealed that a confined bismuth layer at the graphene/SiC interface can be reversibly switched between a topologically trivial precursor phase and the quantum spin Hall insulator bismuthene. Here, we present a detailed spin- and angle-resolved photoelectron spectroscopy study of both structures, resolving the spin texture of their low-energy electronic states. Owing to the strong intrinsic spin-orbit coupling of bismuth and the asymmetric confinement potential at the interface, the valence bands of both structures are Rashba-split. We demonstrate the expected spin-momentum locking for both phases and Kramers' doublets through the investigation of the valence bands' spin polarization at multiple positions in reciprocal space.