Tunneling Transport in Gapped Graphene through a Bias-Tunable Potential Barrier*

We have investigated electron tunneling and transport properties for graphene through a non-square barrier with a finite slop in the potential profile. We have developed a new methodology based on thefinite-difference solution of the scattering equations for a Dirac electron, and have also built a perturbation theory for the electron transmission for the case with a small slope. Both gapped and gapless graphene materials have been considered in our calculations. All these predicted properties are expected to have the highest importance for novel electronic and optical devices.