We investigate electronic transport property of a graphene monolayer covered by a graphene nanoribbon. We demonstrate that electronic transmission of a monolayer can be reduced when covered by a nanoribbon. The transmission reduction occurs at differ
ent energies determined by the width of nanoribbon. We explain the transmission reduction by using interference between wavefunctions in the monolayer and the nanoribbon. Furthermore, we show the transmission reduction of a monolayer is combinable when covered by more than one nanoribbon and propose a concept of combination of control for nano-application design.
