Nanoscale and edge effect on electronic properties of graphene

A brief review is given on nanoscale and edge effect on electronic properties of graphene from theoretical point of view. The presence of edges in graphene has strong implications for low-energy spectrum of the π electrons. The topics include the electronic states of graphene nanoribbons on the basis of tight-binding model, ferrimagnetic edge spin polarization due to the edge states and half-metallic states induced by the electric field effect or edge chemical modification.