Quantum pumping in a ballistic graphene bilayer

摘要

We investigate quantum pumping of massless Dirac fermions in an ideal (impurity free) double layer of graphene. The pumped current is generated by adiabatic variation in two gate voltages in the contact regions to a weakly doped double graphene sheet. At the Dirac point and for a wide bilayer with width W? length L, we find that the pumped current scales linearly with the interlayer coupling length l_⊥ for L/l_⊥ ? 1, is maximal for L/l_⊥～1, and crosses over to a In(L/l_⊥)/(L/l_⊥) dependence for L/l_⊥?1. We compare our results with the behavior of the conductance in the same system and discuss their experimental feasibility.