Entanglement swapping with photons generated on-demand by a quantum dot

TL;DR

This paper demonstrates on-demand entanglement swapping using a quantum dot source, showing solid-state emitters are viable for scalable quantum networks and providing a theoretical model for performance analysis.

Contribution

It presents the first successful all-photonic entanglement swapping with quantum dot sources and offers a theoretical framework for evaluating their performance.

Findings

Successful entanglement swapping with quantum dot photons.

Development of a quantitative theoretical model.

Solid-state quantum emitters are suitable for quantum networking.

Abstract

Photonic entanglement swapping, the procedure of entangling photons without any direct interaction, is a fundamental test of quantum mechanics and an essential resource to the realization of quantum networks. Probabilistic sources of non-classical light can be used for entanglement swapping, but quantum communication technologies with device-independent functionalities demand for push-button operation that, in principle, can be implemented using single quantum emitters. This, however, turned out to be an extraordinary challenge due to the stringent requirements on the efficiency and purity of generation of entangled states. Here we tackle this challenge and show that pairs of polarization-entangled photons generated on-demand by a GaAs quantum dot can be used to successfully demonstrate all-photonic entanglement swapping. Moreover, we develop a theoretical model that provides quantitative insight on the critical figures of merit for the performance of the swapping procedure. This work shows that solid-state quantum emitters are mature for quantum networking and indicates a path for scaling up.