Transport properties of AB-stacked bilayer graphene nanoribbons in an electric field

The electronic and thermal properties of AB-stacked bilayer graphene nanoribbons subject to the influences of a transverse electric field are investigated theoretically, including their transport properties. The dispersion relations are found to exhibit a rich dependence on the interlayer interactions, the field strength, and the geometry of the layers. The interlayer coupling will modify the subband curvature, create additional band-edge states, change the subband spacing or energy gap, and separate the partial flat bands. The bandstructures will be symmetric or asymmetric about the Fermi energy for monolayer or bilayer nanoribbons, respectively. The inclusion of a transverse electric field will further alter the bandstructures and lift the degeneracy of the partial flat bands. The chemical-potential-dependent electrical and thermal conductance exhibit a stepwise increase behavior. Variations in the electronic structures with field strength will be reflected in the electrical and thermal conductance. Prominent peaks, as well as single-shoulder and multi-shoulder structures in the electrical and thermal conductance are predicted when varying the electric field strength. The features of the conductance are found to be strongly dependent on the field strength, the geometry, interlayer interactions and temperature.