Nonlocal Andreev transport through an interacting quantum dot

We investigate subgap transport through a single-level quantum dot tunnel coupled to one superconducting and two normal-conducting leads. Despite the tendency of a large charging energy to suppress the equilibrium proximity effect, a finite Andreev current through the dot can be achieved in nonequilibrium situations. We propose two schemes to identify nonlocal Andreev transport. In one of them, the presence of strong Coulomb interaction leads to negative values of the nonlocal conductance as a clear signal of nonlocal Andreev transport.