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

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…

• DF
  Deutsche Forschungsgemeinschaft

  Awards: SCHA1510/5, award316580, award316582, award316581, SPP 1666
• ER
  European Research Council

  Awards: ERC-StG-Thomale-336012, award316583