Generating two continuous entangled microwave beams using a dc-biased Josephson junction
Abstract
We show experimentally that a dc-biased Josephson junction in series with two microwave resonators emits entangled beams of microwaves leaking out of the resonators. In the absence of a stationary phase reference for characterizing the entanglement of the outgoing beams, we measure second-order coherence functions for proving entanglement up to an emission rate of 2.5 billion photon pairs per second. The experimental results are found in quantitative agreement with theory, proving that the low frequency noise of the dc bias is the main limitation for the coherence time of the entangled beams. This agreement allows us to evaluate the entropy of entanglement of the resonators, and to identify the improvements that could bring this device closer to a useful bright source of entangled microwaves for quantum-technological applications.
Cite
@article{arxiv.2010.03376,
title = {Generating two continuous entangled microwave beams using a dc-biased Josephson junction},
author = {A. Peugeot and G. Ménard and S. Dambach and M. Westig and B. Kubala and Y. Mukharsky and C. Altimiras and P. Joyez and D. Vion and P. Roche and D. Esteve and P. Milman and J. Leppäkangas and G. Johansson and M. Hofheinz and J. Ankerhold and F. Portier},
journal= {arXiv preprint arXiv:2010.03376},
year = {2021}
}