Monolayer graphene panorama, Majorana modes and Longitudinal conductivity

Abstract: We take a wide-angle view of the problem of monolayer graphene where the valley-mixing and the spin-degeneracy lifting are assumed to be possible by wedging in the requisite ingredients, viz. the atomically sharp scatterers and the strong Rashba coupling dominating over the intrinsic spin-orbit coupling. This leads to eight Majorana-like modes (quasi-particles which are self-conjugate) close to the experimentally inaccessible Dirac points. Using Kubo formula we also show that the semi-classical diffusive (longitudinal) conductivity is nearly (2.018 e2/h) at room temperature for the disordered system. Though this is an overestimation, we have been, never-the-less, able to qualitatively capture the fact that the room temperature conductivity of graphene is finite and the contribution to the conductivity arises from the momentum very close to the Dirac points.