Spin-orbit coupling in graphene
We deploy quasi-particle interference imaging using a scanning tunneling microscope to probe the presence, nature and strength of proximity induced spin-orbit coupling (SOC) in single layer graphene (SLG) on WSe2. In the presence of SOC, the pseudo-spin texture is modified, enabling intravalley backscattering forbidden in isolated SLG. This backscattering is detected through a characteristic small momentum ring around the gamma point in the Fourier transform of a large conductance map. Fitting the intensity of this ring to a weak coupling Hamiltonian, we identify the contributions of a Rashba and a valley-Zeeman SOC term, and exclude the contribution of a mass gap to the observed intravalley backscattering.
Collaboration with Alberto Morpurgo and Louk Rademaker, University of Geneva.