The conductance of metallic graphene nanoribbons (GNRs) with single defects and weak disorder at their edges is investigated in a tight-binding model. We find that a single edge defect will induce quasi-localized states and consequently cause zero-conductance dips. The center energies and breadths of such dips are strongly dependent on the geometry of GNRs. Armchair GNRs are much more sensitive to a vacancy than zigzag GNRs, but are less sensitive to a weak scatter. More importantly, we find that with a weak disorder, zigzag GNRs will change from metallic to semiconducting due to Anderson localization. But a weak disorder only slightly affects the conductance of armchair GNRs. The influence of edge defects on the conductance will decrease when the widths of GNRs increase.
@article{arxiv.cond-mat/0609009,
title = {Quantum conductance of graphene nanoribbons with edge defects},
author = {T. C. Li and Shao-Ping Lu},
journal= {arXiv preprint arXiv:cond-mat/0609009},
year = {2008}
}