Nonlocal Cooper pair Splitting in a pSn Junction

TL;DR

This paper proposes a novel pSn junction design that achieves perfect Cooper pair splitting via crossed Andreev reflection, utilizing bandstructure energy filtering, promising high-quality entanglement sources.

Contribution

It introduces a new pSn junction model with energy filtering for perfect Cooper pair splitting, extending existing theories beyond the Andreev approximation.

Findings

Large crossed Andreev reflection current despite momentum mismatch

Predicted 100% purity of nonlocal entangled current

Straightforward experimental design proposed

Abstract

Perfect Cooper pair splitting is proposed, based on crossed Andreev reflection (CAR) in a p-type semiconductor - superconductor - n-type semiconductor (pSn) junction. The ideal splitting is caused by the energy filtering that is enforced by the bandstructure of the electrodes. The pSn junction is modeled by the Bogoliubov-de Gennes equations and an extension of the Blonder-Tinkham-Klapwijk theory beyond the Andreev approximation. Despite a large momentum mismatch, the CAR current is predicted to be large. The proposed straightforward experimental design and the 100% degree of pureness of the nonlocal current open the way to pSn structures as high quality sources of entanglement.