Bismuthene on a SiC substrate: A candidate for a high-temperature quantum spin Hall material

• Autores: F. Reis, G. Li, L. Dudy
• Localización: Science, ISSN 0036-8075, Vol. 357, Nº 6348, 2017, págs. 287-290
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Quantum spin Hall materials hold the promise of revolutionary devices with dissipationless spin currents but have required cryogenic temperatures owing to small energy gaps. Here we show theoretically that a room-temperature regime with a large energy gap may be achievable within a paradigm that exploits the atomic spin-orbit coupling. The concept is based on a substrate-supported monolayer of a high–atomic number element and is experimentally realized as a bismuth honeycomb lattice on top of the insulating silicon carbide substrate SiC(0001). Using scanning tunneling spectroscopy, we detect a gap of ~0.8 electron volt and conductive edge states consistent with theory. Our combined theoretical and experimental results demonstrate a concept for a quantum spin Hall wide-gap scenario, where the chemical potential resides in the global system gap, ensuring robust edge conductance.