Crossover of the conductivity of zigzag graphene nanoribbon connected by normal metal contacts

The transport property of zigzag graphene nanoribbon (ZGNR) connected by two normal metal contacts is investigated by Landauer–Buttiker formula combined with transfer matrix method. In addition to even–odd parity, we found that the conductivity is completely determined by the width-to-length ratio. For certain wide ZGNR with even number carbon atoms in the width direction, the conductivity dependence on the length changes from linearly to inversely, when the length approaches the thermodynamic limit, as the transport property is quite different for different aspect of ZGNR.