Entanglement of Gaussian states and the applicability to quantum key distribution over fading channels

Usenko VC, Heim B, Peuntinger C, Wittmann C, Marquardt C, Leuchs G, Filip R (2012)

Publication Type: Journal article

Publication year: 2012

Journal

New Journal of Physics Institute of Physics: Open Access Journals / Institute of Physics (IoP) and Deutsche Physikalische Gesellschaft

Book Volume: 14

Article Number: 093048

DOI: 10.1088/1367-2630/14/9/093048

Abstract

Entanglement properties of Gaussian states of light as well as the security of continuous variable quantum key distribution with Gaussian states in free-space fading channels are studied. These qualities are shown to be sensitive to the statistical properties of the transmittance distribution in the cases when entanglement is strong or when channel excess noise is present. Fading, i.e. transmission fluctuations, caused by beam wandering due to atmospheric turbulence, is a frequent challenge in free-space communication. We introduce a method of fading discrimination and subsequent post-selection of the corresponding sub-states and show that it can improve the entanglement resource and restore the security of the key distribution over a realistic fading link. Furthermore, the optimal post-selection strategy in combination with an optimized entangled resource is shown to drastically increase the protocol's robustness to excess noise, which is confirmed for experimentally measured fading channel characteristics. The stability of the result against finite data ensemble size and imperfect channel estimation is also addressed. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Authors with CRIS profile

Christoph Marquardt Institut für Optik, Information und Photonik Gerhard Leuchs

Involved external institutions

Palacky University Olomouc / Univerzita Palackého v Olomouci CZ Czech Republic (CZ) Max-Planck-Institut für die Physik des Lichts (MPL) / Max Planck Institute for the Science of Light DE Germany (DE)

How to cite

APA:

Usenko, V.C., Heim, B., Peuntinger, C., Wittmann, C., Marquardt, C., Leuchs, G., & Filip, R. (2012). Entanglement of Gaussian states and the applicability to quantum key distribution over fading channels. New Journal of Physics, 14. https://doi.org/10.1088/1367-2630/14/9/093048

MLA:

Usenko, Vladyslav C., et al. "Entanglement of Gaussian states and the applicability to quantum key distribution over fading channels." New Journal of Physics 14 (2012).

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