Ballistic Transport of Epitaxial Graphene Nanoribbons on SiC

Exceptional ballistic transport was observed in sidewall epitaxial graphene nanoribbons on SiC (SWGNRs) at room temperature [1]. These objects are of fundamental interest as they provide a direct access to charge neutral graphene with excellent transport properties. Here, beyond sidewalls, we fabricate epitaxial graphene nanoribbons on different crystal faces on SiC, including Si-face and non-polar facets. We introduce amorphous carbon as contact pads and high temperature annealing to reduce the edge roughness of ribbons and the contamination from resist residue. Then we discuss transport measurment and magnetoresistance results of graphene nanoribbons on Si-face as well as on non-polar SiC facets, which might reveal the nature of the ballistic channels in SWGNRs.
[1] J. Baringhaus et al. Nature 506, 349 (2014).