Twist-angle dependent proximity induced spin-orbit coupling in graphene/transition-metal dichalcogenide and graphene/topological insulator heterostructures
Institute for Theoretical Physics, University of Regensburg, 93053 Regensburg, Germany
We investigate the proximity-induced spin-orbit coupling in twisted heterostructures of graphene/transition-metal dichalcogenides (MoS2, WS2, MoSe2, and WSe2) as well as graphene/topological insulators (Bi2Se3 and Bi2Te3) from first principles. The band structures of serveral supercells are fitted around the Dirac point to an established spin-orbit Hamiltonian, yielding the twist angle dependencies of the spin-orbit couplings. While for most structures a mix of Rashba and valley-Zeeman spin-orbit coupling is present, we also witness the emergence of Kane-Mele spin-orbit coupling in graphene/topological insulator structures at 30° twist angle. Additionally, for twisted supercells we observe a radial component of the in-plane spin structure around the Dirac cone, which can be used to induce collinear charge-to-spin conversion.
host: Martin Gmitra