Pirandola, S;
Laurenza, R;
Ottaviani, C;
Banchi, L;
(2017)
Fundamental limits of repeaterless quantum communications.
Nature Communications
, 8
, Article 15043. 10.1038/ncomms15043.
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Abstract
Quantum communications promises reliable transmission of quantum information, efficient distribution of entanglement and generation of completely secure keys. For all these tasks, we need to determine the optimal point-to-point rates that are achievable by two remote parties at the ends of a quantum channel, without restrictions on their local operations and classical communication, which can be unlimited and two-way. These two-way assisted capacities represent the ultimate rates that are reachable without quantum repeaters. Here, by constructing an upper bound based on the relative entropy of entanglement and devising a dimension-independent technique dubbed ‘teleportation stretching’, we establish these capacities for many fundamental channels, namely bosonic lossy channels, quantum-limited amplifiers, dephasing and erasure channels in arbitrary dimension. In particular, we exactly determine the fundamental rate-loss tradeoff affecting any protocol of quantum key distribution. Our findings set the limits of point-to-point quantum communications and provide precise and general benchmarks for quantum repeaters.
| Type: | Article |
|---|---|
| Title: | Fundamental limits of repeaterless quantum communications |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1038/ncomms15043 |
| Publisher version: | http://doi.org/10.1038/ncomms15043 |
| Language: | English |
| Additional information: | © The Author(s) 2017. This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
| Keywords: | Science & Technology, Multidisciplinary Sciences, Science & Technology - Other Topics, KEY DISTRIBUTION, ERROR-CORRECTION, CRYPTOGRAPHY, TELEPORTATION, ENTANGLEMENT, INFORMATION, CHANNELS, CAPACITY, INTERNET, DISCORD |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/1502565 |
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