Engineering charge tunable one dimensional molecular array towards supercritical collapse states in graphene

The ability to modify the electronic properties of monolayer graphene via molecular control creates new opportunities for fabricating nanoscale hybrid devices. Understanding the charge transfer properties and resulting electronic behavior of molecule/graphene interfaces is essential for tuning the electronic and magnetic characteristics of these hybrid devices. By controlling charged impurities through molecular self-assembly on a gated graphene device, we can switch the charge state of the molecule and engineer the wave function of relativistic electrons in graphene. Scanning tunneling spectroscopy is used to locally probe the electronic structure of graphene and the molecular nanostructures. Molecular self-assembly is controlled by the molecular coverage and edge-templated self-assembly in UHV condition. Relativistic electrons on graphene undergo a transition from subcritical to a supercritical regime as the packing density of the charged molecule array is increased. We found that one-dimensional supercritical states emerge in graphene when we tune the molecular array below the critical spacing.