We propose a quantum pump mechanism based on the particular properties of
graphene, namely chirality and bipolarity. The underlying physics is the
excitation of evanescent modes entering a potential barrier from one
lead, while those from the other lead do not reach the driving region.
This induces a large nonequilibrium current with electrons stemming from
a broad range of energies, in contrast to the narrow resonances that
govern the corresponding effect in semiconductor heterostructures.
Moreover, the pump mechanism in graphene turns out to be robust, with a
simple parameter dependence, which is beneficial for applications.
Numerical results from a Floquet scattering formalism are complemented
with analytical solutions for small to moderate driving.
To begin viewing slides, click on the first slide below. (Or, view as pdf.)
Author entry (protected)