Tunneling conductance in gapped graphene-based normal metal–insulator–superconductor junctions: Case of massive Dirac electrons

We study the quantum transport property in a gapped graphene-based normal metal–insulator–superconductor junctions ( NG/ IG/ SG), in the limit of a thin barrier. The charged fermions in NG/ IG/ SG structure are treated as massive relativistic particles. Based on Andreev and normal reflections in normal-superconductor graphene-based junction and BTK formalism, the tunneling conductance’s in terms of some different electrostatic superconductor, U 0 and barrier, V 0 potential are obtained. Using the experimental based values of the Fermi energy in the NG and SG ( E FN and E FN + U 0, respectively), energy gap in graphene 2 mv F 2 and superconducting order parameter, Δ, it is shown that the conductance spectra of such system represent a new behavior, i.e. if we take | E FN - mv F 2 | → 0 , it becomes as a step function of V 0. This behavior of charge transportation can be considered as a nano switch.