Guided modes in a graphene barrier waveguide

A graphene-based barrier can act as an electron waveguide. The characteristics of the guided modes in the waveguide are investigated. The conditions for the incident energy that generates the guide modes are different between the barrier waveguide and the graphene quantum well waveguides. Guided modes only exist in the case of Klein tunneling, and cannot be generated in the case of classical motion in the barrier waveguide, however guided modes can be generated for both the classical motion and Klein tunneling cases in the well waveguides. The fundamental mode is absent in the graphene barrier waveguide, similar to that in the graphene well waveguides in the Klein tunneling case, while the barrier waveguide supports fewer guided modes. In spite of the vanishing effective mass of electrons and holes, the graphene barrier waveguide can guide electronic waves, which differs from the conventional semiconductor homostructure barrier, which cannot form a waveguide. The graphene-based barrier waveguides are potentially useful in future electron guided-wave integrated circuits which could perform optical-like processing.