17,362 research outputs found
Photonic Engineering for CV-QKD over Earth-Satellite Channels
Quantum Key Distribution (QKD) via satellite offers up the possibility of
unconditionally secure communications on a global scale. Increasing the secret
key rate in such systems, via photonic engineering at the source, is a topic of
much ongoing research. In this work we investigate the use of photon-added
states and photon-subtracted states, derived from two mode squeezed vacuum
states, as examples of such photonic engineering. Specifically, we determine
which engineered-photonic state provides for better QKD performance when
implemented over channels connecting terrestrial receivers with Low-Earth-Orbit
satellites. We quantify the impact the number of photons that are added or
subtracted has, and highlight the role played by the adopted model for
atmospheric turbulence and loss on the predicted key rates. Our results are
presented in terms of the complexity of deployment used, with the simplest
deployments ignoring any estimate of the channel, and the more sophisticated
deployments involving a feedback loop that is used to optimize the key rate for
each channel estimation. The optimal quantum state is identified for each
deployment scenario investigated.Comment: Updated reference lis
Long-Distance Quantum Communication with Entangled Photons using Satellites
The use of satellites to distribute entangled photon pairs (and single
photons) provides a unique solution for long-distance quantum communication
networks. This overcomes the principle limitations of Earth-bound technology,
i.e. the narrow range of some 100 km provided by optical fiber and terrestrial
free-space links.Comment: 12 pages, 7 figures; submitted to IEEE Journal of Selected Topics in
Quantum Electronics, special issue on "Quantum Internet Technologies
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