Pirandola, Stefano orcid.org/0000-0001-6165-5615, Ottaviani, Carlo orcid.org/0000-0002-0032-3999, Jacobsen, Christian S. et al. (4 more authors) (2021) Environment-assisted bosonic quantum communications. npj Quantum Information. 77. ISSN 2056-6387
Abstract
We consider a quantum relay which is used by two parties to perform several continuous-variable protocols of quantum communication, from entanglement distribution (swapping and distillation), to quantum teleportation, and quantum key distribution. The theory of these protocols is suitably extended to a non-Markovian model of decoherence characterized by correlated Gaussian noise in the bosonic environment. In the worst case scenario where bipartite entanglement is completely lost at the relay, we show that the various protocols can be reactivated by the assistance of classical (separable) correlations in the environment. In fact, above a critical amount, these correlations are able to guarantee the distribution of a weaker form of entanglement (quadripartite), which can be localized by the relay into a stronger form (bipartite) that is exploitable by the parties. Our findings are confirmed by a proof-of-principle experiment where we show, for the first time, that memory effects in the environment can drastically enhance the performance of a quantum relay, well beyond the single-repeater bound for quantum and private communications.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © The Author(s) 2021 Main text plus Supplemental Material. 30 pages. 23 figures. Expands arXiv:1505.07457 and includes new results |
Keywords: | quant-ph,physics.optics |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Computer Science (York) |
Depositing User: | Pure (York) |
Date Deposited: | 19 Apr 2021 11:50 |
Last Modified: | 21 Jan 2025 17:53 |
Published Version: | https://doi.org/10.1038/s41534-021-00413-2 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1038/s41534-021-00413-2 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:173192 |