  We investigate a graphene quantum pump, adiabatically driven by two thin
potential barriers vibrating around their equilibrium positions. For the highly
doped leads, the pumped current per mode diverges at the Dirac point due to the
more efficient contribution of the evanescent modes in the pumping process. The
pumped current shows an oscillatory behavior with an increasing amplitude as a
function of the carrier concentration. This effect is in contrast to the
decreasing oscillatory behavior of the similar normal pump. The graphene pump
driven by two vibrating thin barriers operates more efficient than the graphene
pump driven by two oscillating thin barriers.
