▎ 摘　　要

The transport properties of devices made from graphene ribbons with either perfectly flat or corrugated structures and sandwiched between metallic electrodes are investigated with first principles method. The relaxed geometry of the devices is obtained by using molecular dynamics based on the Tersoff's potential, while the transport is evaluated with a combination of density functional theory and the nonequilibrium Green's function method. In general, the transport properties of the two graphene structures differ from each other. In particular, we find that corrugation greatly enhances the conductance through the device. (c) 2008 American Institute of Physics.