Designing transport properties of graphene nanoribbon junctions*

Graphene nanoribbons (GNRs) have recently emerged as promising candidates for next-generation electronic devices, including the realization of all-graphene nanocircuitry. Junctions connecting two or more GNRs are the elementary components of GNR circuits. We systematically address the electronic transport properties of 60°- and 120°-angled junctions connecting a pair of GNR leads of identical width and chirality utilizing tight-binding model calculations. An exhaustive exploration of GNR junctions carried out by screening over 50,000 configurations allows us to formulate general guidelines into engineering transport properties GNR circuits. For instance, we find that 120°-angled junctions with sublattice imbalance have a perfect transmission via a resonant state occurring at zero energy, and thus identified as ideal GNR interconnects.