Adiabatic Pumping of Electrons in Mesoscopic Systems coupled to a Superconducting Lead

摘要

We derive a general scattering-matrix formula for the pumped current through amesoscopic region attached to a normal and a superconducting lead. As an application of thisresult we calculate the current pumped through a quantum dot in the Coulomb blockade regimecoupled to a superconducting lead. Andreev reflection is shown to enhance the pumped currentby up to a factor of 4 in case of equal coupling to the leads. We find that this enhancement canstill be further increased for slightly asymmetric coupling.