Kondo-enhanced Andreev transport in single self-assembled InAs quantum dots contacted with normal and superconducting leads

Abstract

We study transport in self-assembled InAs quantum dots contacted with one superconducting and one normal-metal electrode. Low bias transport is dominated by Andreev processes which are sensitive to local correlations such as electron-electron interaction and the Kondo effect. We identify that, for appropriate tunnel coupling with normal and superconducting leads, Andreev transport is enhanced by the Kondo effect and that the Kondo temperature is reduced relative to the normal state due to lack of low-energy excitations with the superconducting lead.