Abstract: A graphene device having a ribbon structure with soft boundaries formed between two thin parallel transport barriers in a “railroad track” configuration. Such a structure permits transport along the ribbon, and also permits transport of electrons across the barriers by means of resonant tunneling through quasi-bound states within the railroad track confinement. The transport barriers can be of any form of so long as transport through the barriers leads to the formation of isolated resonant bands with a transport gap. In some embodiments, the transport barriers can be in the form of a pair of parallel line defects, wherein the line defects delineate the central ribbon section and the two lateral sections. In some such embodiments, the line defects are chemically decorated by the adsorption of diatomic gases. In other embodiments, the transport barriers can be formed by the application of large local potentials directly to the graphene sheet.

Abstract: A graphene device having a ribbon structure with soft boundaries formed between two thin parallel transport barriers in a “railroad track” configuration. Such a structure permits transport along the ribbon, and also permits transport of electrons across the barriers by means of resonant tunneling through quasi-bound states within the railroad track confinement. The transport barriers can be of any form of so long as transport through the barriers leads to the formation of isolated resonant bands with a transport gap. In some embodiments, the transport barriers can be in the form of a pair of parallel line defects, wherein the line defects delineate the central ribbon section and the two lateral sections. In some such embodiments, the line defects are chemically decorated by the adsorption of diatomic gases. In other embodiments, the transport barriers can be formed by the application of large local potentials directly to the graphene sheet.