The coherent electron transport along zig-zag and metallic armchair graphene nanoribbons in the presence of one or two vacancies was investigated. Having in mind atomic scale tunability of the conductance fingerprints, the primary focus was on the effect of the distance to the edges and intervacancy spacings. An involved interplay of vacancies sub-lattice location and nanoribbon edge termination, together with the spacing parameters led to a wide conductance resonance line-shape modification. Turning on a magnetic field introduces a new length scale that unveils counterintuitive aspects of the interplay between purely geometric aspects of the system and the underlying atomic scale nature of graphene.

Tunable Resonances Due to Vacancies in Graphene Nanoribbons. D.A.Bahamon, A.L.C.Pereira, P.A.Schulz: Physical Review B, 2010, 82[16], 165438