Dependence of transport on adatom location for armchair-edge graphene nanoribbons
Abstract
We study the transport property for armchair-edge graphene nanoribbons (AGNRs) with an adatom coupling to a semi-infinite quantum wire. Using the nonequilibrium Green's function approach with tight-binding approximation, we demonstrate that the tunneling current through the system is sensitively dependent on both the AGNR width and adatom location. Interestingly, when the adatom locates onto a carbon atom in the 3jth chain from the edge of a metallic AGNR, the system shows a transmission gap accompanied by a threshold voltage in I-V curve like a semiconducting AGNR. This effect may be useful in scanning tunneling microscopy experimental characterization on graphene samples.
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