Theory of Weak-Field Magnetoresistance in Bilayer Graphene

The magnetoconductivity, which is the correction to the diagonal conductivity proportional to the second power of magnetic-field strength, is calculated in bilayer graphene in the presence of scatterers with long-range potential such as a Gaussian potential and screened Coulomb potential in a self-consistent Born approximation. The magnetoresistivity in a usual Hall bar geometry exhibits prominent double-peak structure in the vicinity of zero energy and remains very small in other regions because of the cancellation with a counter term due to the Hall effect. In a constant broadening approximation, on the other hand, the magnetoresistivity becomes negative and has a sharp double-dip structure. These features are quite similar to those in monolayer graphene.