Thermoelectric and thermal transport in bilayer graphene systems

We numerically study the disorder effect on the thermoelectric and thermal transport in bilayer graphene under a strong perpendicular magnetic field. In the unbiased case, we find that the thermoelectric transport has similar properties as in monolayer graphene, i.e., the Nernst signal has a peak at the central Landau level (LL) with a height of the order of k_B/e and changes sign near other LLs, while the thermopower has an opposite behavior. We attribute this to the coexistence of particle and hole LLs around the Dirac point. When a finite interlayer bias is applied and a band gap is opened, it is found that the transport properties are consistent with those of a band insulator. We further study the thermal transport from electronic origin and verify the validity of the generalized Weidemann-Franz law.