Effect of magnetic field on electronic transport in a bilayer graphene nanomesh.

We report on the observation of an unexpected sudden increase of resistance in bilayer graphene nanomesh (GNM) in the temperature range 270 ∼ 300 K that is strongly dependent on the magnetic field strength. We conjecture that the sharp increase in resistance originates from ripple scattering as induced by substrate roughness. The observed result is evidence of extrinsic corrugation in bilayer GNM as an additional scattering source that contributes to significant resistance. The observed weak localization in the GNM indicates intervalley scattering induced by lattice defects acts as resonant scatterers attribute to the high D peak. Magnetotransport measurement strongly supports that the charge inhomogeneity related to the intrinsic disorder in bilayer GNM and the positive magnetoresistance shows a linear behavior with magnetic field strength. Potentially, the observed phenomena, therefore, point to a clear pathway towards practical application of bilayer GNM and to the design of a graphene magnetic sensor that can be manipulated by a magnetic field and a new generation of spintronics.