Quantum transport properties of zigzag graphene nanoribbons

We have studied the quantum transport properties of zigzag graphene nanoribbons under periodic or Möbius boundary conditions connected to one-dimensional leads using the nonequilibrium Greenʹs 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 Möbius boundary condition, which is explained by the breaking of the AB-bipartite lattice symmetry.