Fabrication and Characterization of Monolayer Graphene Nanostructures

   Graphene nanostructures offer a unique platform for exploring novel quantum phenomena arising from confined charged carriers.  In order to study these phenomena, precise geometry and high-quality edges are required. Common lithographic techniques such as Reactive Ion Etching (RIE) can be used to mechanically define device geometry at the cost of unwanted etching byproducts. Furthermore, the lack of a bandgap in monolayer graphene has limited the use of electrostatically defined geometries to the high magnetic field regime.  Here we will discuss fabrication of mechanically defined graphene constrictions using AFM based nanolithography and improvements in techniques used to incorporate the nano-structures into vdW heterostructures. We also present transport measurements of these constrictions at both zero and high magnetic fields, extending into the quantum Hall regime.