Distillation of mixed-state continuous-variable entanglement by photon subtraction

Journal Article · Wed Dec 15 04:00:00 EST 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.82.062316· OSTI ID:21528845

Shengli, Zhang; Loock, Peter van ^[1]

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1. Optical Quantum Information Theory Group, Max Planck Institute for the Science of Light, Guenther-Scharowsky-Str. 1/Bau 26, D-91058 Erlangen (Germany) and Institute of Theoretical Physics I, Universitaet Erlangen-Nuernberg, Staudstr. 7/B2, D-91058 Erlangen (Germany)

We present a detailed theoretical analysis for the distillation of one copy of a mixed two-mode continuous-variable entangled state using beam splitters and coherent photon-detection techniques, including conventional on-off detectors and photon-number-resolving detectors. The initial Gaussian mixed-entangled states are generated by transmitting a two-mode squeezed state through a lossy bosonic channel, corresponding to the primary source of errors in current approaches to optical quantum communication. We provide explicit formulas to calculate the entanglement in terms of logarithmic negativity before and after distillation, including losses in the channel and the photon detection, and show that one-copy distillation is still possible even for losses near the typical fiber channel attenuation length. A lower bound for the transmission coefficient of the photon-subtraction beam splitter is derived, representing the minimal value that still allows to enhance the entanglement.

• OSTI ID: 21528845
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 6 Vol. 82; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATTENUATION
BEAM SPLITTING
BOSONS
COMMUNICATIONS
DETECTION
ELEMENTARY PARTICLES
ERRORS
MASSLESS PARTICLES
MIXED STATE
PHOTONS
QUANTUM ENTANGLEMENT
QUANTUM TELEPORTATION
TRANSMISSION