Carbon Nanotubes as Cooper Pair Beam Splitters

TL;DR

This paper demonstrates that carbon nanotube-based double quantum dots can act as tunable beam splitters for Cooper pairs, enabling new experiments with spin-entangled electrons in quantum optics-like setups.

Contribution

It introduces a method to control Crossed Andreev Reflections in carbon nanotube devices, advancing quantum electron optics research.

Findings

Evidence of tunable Crossed Andreev Reflections

Device operation as Cooper pair beam splitters

Potential for quantum optics experiments with entangled electrons

Abstract

We report on conductance measurements in carbon nanotube based double quantum dots connected to two normal electrodes and a central superconducting finger. By operating our devices as beam splitters, we provide evidence for Crossed Andreev Reflections \textit{tunable in situ}. This opens an avenue to more sophisticated quantum optics-like experiments with spin entangled electrons.