Non-local Andreev transport through an interacting quantum dot

TL;DR

This paper studies how non-local Andreev transport occurs in an interacting quantum dot connected to superconducting and normal leads, highlighting non-equilibrium conditions and Coulomb interaction effects.

Contribution

It introduces two schemes to detect non-local Andreev transport, emphasizing the role of Coulomb interactions and non-equilibrium conditions.

Findings

Finite Andreev current can occur despite large charging energy.

Negative non-local conductance signals non-local Andreev transport.

Proposed detection schemes for non-local Andreev processes.

Abstract

We investigate sub-gap 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 non-equilibrium situations. We propose two schemes to identify non-local Andreev transport. In one of them, the presence of strong Coulomb interaction leads to negative values of the non-local conductance as a clear signal of non-local Andreev transport.