The design and fabrication of robust metallic states in graphene nanoribbons (GNRs) is a significant challenge since lateral quantum confinement and many-electron interactions tend to induce electronic band gaps when graphene is patterned at nanometer length scales. Recent developments in bottom-up synthesis have enabled the design and characterization of atomically-precise GNRs, but strategies for realizing GNR metallicity have been elusive. Here we demonstrate a general technique for inducing metallicity in GNRs by inserting a symmetric superlattice of zero-energy modes into otherwise semiconducting GNRs. We verify the resulting metallicity using scanning tunneling spectroscopy as well as first-principles density-functional theory and tight binding calculations. Our results reveal that the metallic bandwidth in GNRs can be tuned over a wide range by controlling the overlap of zero-mode wavefunctions through intentional sublattice symmetry-breaking.
@article{arxiv.1911.00601,
title = {Inducing Metallicity in Graphene Nanoribbons via Zero-Mode Superlattices},
author = {Daniel J. Rizzo and Gregory Veber and Jingwei Jiang and Ryan McCurdy and Ting Cao and Christopher Bronner and Ting Chen and Steven G. Louie and Felix R. Fischer and Michael F. Crommie},
journal= {arXiv preprint arXiv:1911.00601},
year = {2020}
}
Comments
The first three authors listed contributed equally