▎ 摘　　要

We have studied the quantum transport properties of zigzag graphene nanoribbons under periodic or Mobius boundary conditions connected to one-dimensional leads using the nonequilibrium Green's function method with a tight-binding scheme. We reveal the existence of a current path originating from the edge states of the graphene nanoribbons. We have found that the conduction channel at the Fermi energy under the periodic boundary condition vanishes under the Mobius boundary condition, which is explained by the breaking of the AB-bipartite lattice symmetry. (C) 2010 Elsevier B.V. All rights reserved.