Electron transport in quantum antidots made of four-terminal graphene ribbons

Electronic and transport properties of two- and four-terminal graphene nanoribbons are studied taking into account different configurations of quantum antidot potentials, designed at a central conductor. Local density of states maps the electronic distribution changes induced by the antidot potentials and highlights localization effects at the neighboring vacancy sites. Depending on the position, extension, and symmetry of such antidots, we found delocalization of electronic states leading to particular conduction paths along the central region. The origin of dips and maxima in the conductance, and full transport suppression was studied within a microscopic scenario using real-space Green function formalism. The combination of antidot potentials and extra terminals in the device model has shown to generate a variety of transport responses that may be experimentally tuned. (C) 2009 American Institute of Physics. [doi:10.1063/1.3259408]