Abstract
We investigate theoretically the transport current through a double-bended graphene nanoribbon where ZGNR is set between two AGNR leads. After the introduction of graphene and graphene nanoribbon, we use the tight-binding model to describe an A-Z-AGNR system and then modify both the recursive green function method and the boundary conditions proposed by T. Ando to suit our study. We develop a program which is capable of flexible calculation. We simulate currents under different conditions, with a lateral electric field applied on the portion of ZGNR. The results suggest that the appropriate lateral electric field could turn off the current and the device could be controlled by field effect. The transmission oscillates when changing the lateral electric field, the length of ZGNR, and the energy of incident electron. This oscillation is due to the coherent resonant tunneling, which happens when the propagating electron bounces back and forth between the two ends of ZGNR and satisfies the constructive interference condition.