Witnessing effective entanglement in a continuous variable prepare-and-measure setup and application to a quantum key distribution scheme using postselection

Journal Article · Sun Oct 15 00:00:00 EDT 2006 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.74.042326· OSTI ID:20857844

Lorenz, S; Andersen, U L; Leuchs, G ^[1]; Rigas, J; Heid, M; Luetkenhaus, N ^[2]

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1. Institute of Optics, Information and Photonics, Universitaet Erlangen-Nuernberg, Guenther-Scharowsky-Strasse 1/Bau 24, D-91058 Erlangen (Germany)
2. Institute of Theoretical Physics I, Universitaet Erlangen-Nuernberg, Staudtstrasse 7/B2, D-91058 Erlangen (Germany)

We report an experimental demonstration of effective entanglement in a prepare-and-measure type of quantum key distribution protocol. Coherent polarization states and heterodyne measurement to characterize the transmitted quantum states are used, thus enabling us to reconstruct directly their Q function. By evaluating the excess noise of the states, we experimentally demonstrate that they fulfill a nonseparability criterion previously presented by Rigas et al. [J. Rigas, O. Guehne, and N. Luetkenhaus, Phys. Rev. A 73, 012341 (2006)]. For a restricted eavesdropping scenario, we predict key rates using postselection of the heterodyne measurement results.

• OSTI ID: 20857844
• Journal Information: Physical Review. A, Vol. 74, Issue 4; Other Information: DOI: 10.1103/PhysRevA.74.042326; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
DISTRIBUTION
ENERGY LEVELS
INFORMATION THEORY
NOISE
POLARIZATION
QUANTUM CRYPTOGRAPHY
QUANTUM ENTANGLEMENT