Large negative transconductance in multilayer graphene: The role of intersubband scattering

We calculate the transport properties of multilayer graphene, considering the effect of multisubband scattering in a high density regime, where higher subbands are occupied by charge carriers. To calculate the conductivity of multilayer graphene, we use the coupled multiband Boltzmann transport theory while fully incorporating the multiband scattering effects. We show that the allowed scattering channels, screening effects, chiral nature of the electronic structure, and type of impurity scatterings determine the transport behavior of multilayer graphene. We find that the conductivity of multilayer graphene shows a sudden change when the carriers begin to occupy the higher subbands, and therefore a large negative transconductance (NTC) appears as the carrier density varies. These phenomena arise mostly from the intersubband scattering and the change in the density of states at the band touching density. Based on our results, it is possible to build novel devices utilizing the large NTC in multilayer graphene.