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arXiv · 2608.00526

Spin- and Angle-resolved Photoelectron Spectroscopy Study of the Quantum Spin Hall Insulator Bismuthene and its Precursor Phase

Niclas Tilgner·Andres David Peña Unigarro·Susanne Wolff·Mats Leandersson·Craig Polley·Fabian Göhler·Sibylle Gemming·Thomas Seyller·Philip Schädlich
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Abstract

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.

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Niclas Tilgner, Andres David Peña Unigarro, Susanne Wolff, Mats Leandersson, Craig Polley, Fabian Göhler, Sibylle Gemming, Thomas Seyller, Philip Schädlich. 2026-08-01. Spin- and Angle-resolved Photoelectron Spectroscopy Study of the Quantum Spin Hall Insulator Bismuthene and its Precursor Phase. https://arxiv.org/abs/2608.00526

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