Tunneling of Electrons in Graphene via Double Triangular Barrier in External Fields

We study the transmission probability of Dirac fermions in graphene scattered by a triangular double barrier potential in the presence of an external magnetic field. Our system made of two triangular potential barrier regions separated by a well region characterized by an energy gap. Solving our Dirac-like equation and matching the solutions at the boundaries allowed us to express our transmission and reflection coefficients in terms of transfer matrix. We show in particular that the transmission exhibits oscillation resonances that are manifestations of the Klein tunneling effect. The triangular barrier electrostatic field was found to play a key role in controlling the peak of tunneling resistance. However, it only slightly modifies the resonances at oblique incidence and leaves Klein paradox unaffected at normal incidence.Comment: 20 pages, 10 figures. arXiv admin note: substantial text overlap with arXiv:1511.0688