High rate, long-distance quantum key distribution over 250 km of ultra low loss fibres

Stucki, Damien; Walenta, Nino; Vannel, Fabien; Thew, Rob; Gisin, Nicolas; Zbinden, Hugo; Gray, S.; Towery, Christopher; Ten, S.

doi:10.1088/1367-2630/11/7/075003

Cited by 290 publications

(255 citation statements)

References 24 publications

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“…The loss around 800 nm is 2 dB/km. Recent developments have led to the fabrication of ultra-low loss optical fibers, with attenuation as low as 0.16 dB/km (Stucki et al, 2009). Note that the loss remains exponential and that quantum repeater architectures will be useful to increase the transmission rates even if optical fibers with lower losses are developed (unless the attenuation can be reduced dramatically, which seems unlikely in the foreseeable future).…”

Section: F Quantum Channelsmentioning

confidence: 99%

Quantum repeaters based on atomic ensembles and linear optics

et al. 2011

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The distribution of quantum states over long distances is limited by photon loss. Straightforward amplification as in classical telecommunications is not an option in quantum communication because of the no-cloning theorem. This problem could be overcome by implementing quantum repeater protocols, which create long-distance entanglement from shorter-distance entanglement via entanglement swapping. Such protocols require the capacity to create entanglement in a heralded fashion, to store it in quantum memories, and to swap it. One attractive general strategy for realizing quantum repeaters is based on the use of atomic ensembles as quantum memories, in combination with linear optical techniques and photon counting to perform all required operations. Here we review the theoretical and experimental status quo of this very active field. We compare the potential of different approaches quantitatively, with a focus on the most immediate goal of outperforming the direct transmission of photons.

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Section: F Quantum Channelsmentioning

confidence: 99%

Quantum repeaters based on atomic ensembles and linear optics

et al. 2011

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“…In particular, the zero-phonon lines (ZPLs) of V Si -related defects in 4H and 6H polytypes of SiC present spectrally narrow features at near-infrared (NIR) wavelengths (l ZPL ¼ 850-1,200 nm) 10,[14][15][16] . Rayleigh scattering losses in photonic structures are inversely proportional to the fourth power of the wavelength 17,18 , giving almost one order of magnitude lower losses for these defects compared with the nitrogen-vacancy defect in diamond (l ZPL ¼ 637 nm) 19 or the carbon antisite-vacancy pair in SiC (l ZPL ¼ 660 nm) 20 . Similarly, scattering losses at interfaces and signal attenuation in optical fibers decrease with wavelength as well.…”

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confidence: 99%

Engineering near-infrared single-photon emitters with optically active spins in ultrapure silicon carbide

et al. 2015

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Vacancy-related centres in silicon carbide are attracting growing attention because of their appealing optical and spin properties. These atomic-scale defects can be created using electron or neutron irradiation; however, their precise engineering has not been demonstrated yet. Here, silicon vacancies are generated in a nuclear reactor and their density is controlled over eight orders of magnitude within an accuracy down to a single vacancy level. An isolated silicon vacancy serves as a near-infrared photostable single-photon emitter, operating even at room temperature. The vacancy spins can be manipulated using an optically detected magnetic resonance technique, and we determine the transition rates and absorption crosssection, describing the intensity-dependent photophysics of these emitters. The on-demand engineering of optically active spins in technologically friendly materials is a crucial step toward implementation of both maser amplifiers, requiring high-density spin ensembles, and qubits based on single spins.

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“…The COW QKD system was developed by GAP [7]- [10]. A schematic of the configuration is drawn in figure 10.…”

Section: Coherent One-way (Cow) System Time Codingmentioning

confidence: 99%

“…In order to gain a more integral perspective we ignore the dynamic interplay between the pick-up store, the common store and the in/out buffers and consider only the total key in the key store, which is the sum of the key material that is saved as a function of time in each of these entities. Note that in the following, we use the binary prefixes Ki for 2 10 , and Mi for 2 20 (as defined in IEC 60027-2), i.e. 1 KiB (kibibyte) is equal to 1024 bytes, 1 MiB (mebibyte) is equal to 1048 576 bytes.…”

Section: Prototype Operation In Typical Regimesmentioning

confidence: 99%