Thermoelectric-induced unitary Cooper pair splitting efficiency

TL;DR

This paper demonstrates a thermoelectric method to achieve near-perfect Cooper pair splitting efficiency in a quantum dot junction, surpassing previous experimental results by using temperature differences and level tuning.

Contribution

It introduces a novel thermoelectric approach with level tuning to optimize Cooper pair splitting efficiency in a quantum dot system.

Findings

Achieves near-unitary Cooper pair splitting efficiency.

Utilizes temperature difference instead of bias voltage.

Ensures elastic cotunneling transmittance is particle-hole symmetric.

Abstract

Thermoelectric effect is exploited to optimize the Cooper pair splitting efficiency in a Y-shaped junction, which consists of two normal leads coupled to an $s$-wave superconductor via double noninteracting quantum dots. Here, utilizing temperature difference rather than bias voltage between the two normal leads, and tuning the two dot levels such that the transmittance of elastic cotunneling process is particle-hole symmetric, we find currents flowing through the normal leads are totally contributed from the splitting of Cooper pairs emitted from the superconductor. Such a unitary splitting efficiency is significantly better than the efficiencies obtained in experiments so far.