Fabrication of a tunable quantum point contact in bilayer graphene

The realization of a quantum point contact (QPC) in graphene is of interest for both physical and technological reasons. Fabricating a tunable QPC thus far, however, has been technologically challenging due to the inability to electrostatically deplete graphene. Recent advances have allowed for the creation of high mobility dual-gated bilayer samples sandwiched in hexagonal boron nitride. These samples display a robust, tunable band gap, which opens the door to electrostatically defining the conductance channel. In this presentation, we report the fabrication and characterization of point contact structures in high mobility dual-gated bilayer graphene samples employing hBN as both the top and bottom dielectric layer.