Quantum key distribution over a 40-dB channel loss using superconducting single-photon detectors

By Hiroki Takesue, Sae Woo Nam, Qiang Zhang, Robert H. Hadfield, Toshimori Honjo, Kiyoshi Tamaki, Yoshihisa Yamamoto. 2007

747 citations recorded by the source corpus.

We report the first quantum key distribution (QKD) experiment to enable the creation of secure keys over 42 dB channel loss and 200 km of optical fibre. We used the differential phase shift QKD (DPS-QKD) protocol, implemented with a 10-GHz clock frequency and superconducting single-photon detectors (SSPD) based on NbN nanowires. The SSPD offers a very low dark count rate (a few Hz) and small timing jitter (60 ps, full width at half maximum, FWHM). These characteristics allowed us to achieve a 12.1 bit s–1 secure key rate over 200 km of fibre, which is the longest terrestrial QKD over a fibre link yet demonstrated. Moreover, this is the first 10-GHz clock QKD system to enable secure key generation. The keys generated in our experiment are secure against both general collective attacks on individual photons and a specific collective attack on multiphotons, known as a sequential unambiguous state discrimination (USD) attack.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/d09f0813368ee6349814034e0869556d0d95ed85

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Citations in the corpus

The security of practical quantum key distribution (2008, methodology): “The DPS protocol has been already the object of several experimental demonstrations (Diamanti et al., 2006; Takesue et al., 2005, 2007).”
Feasibility of satellite quantum key distribution (2009, background): “Fiber and free-space links have been realized linking nodes at larger and larger distances [9, 10] with higher and higher key generation rates.”
Superconducting nanowire single-photon detectors for quantum information (2020, methodology): “Until now, the best result obtained using SPADs was reported in 2015, where a QKD containing more than 307 km of optical fiber based on a coherent one-way protocol was demonstrated with the best InGaAs/InP SPADs (DEs of 20%–22%, DCR of ~1 cps) [154].”
Single-photon generation and detection (2009, methodology): “The low timing jitter and dark count rate and wide spectrum of detectable wavelengths of SSPDs makes them interesting candidates for use in many applications.”
High rate, long-distance quantum key distribution over 250 km of ultra low loss fibres (2009, methodology): “For example, the separation between the remote locations was 32 cm in the first experimental demonstration [6] and now reaches tens of kilometres [7]–[12] with a record distance of 200 km in the lab [10] and more importantly, up to 150 km just recently in field trials [8].”
Tight finite-key analysis for quantum cryptography (2011, background): “At the same time, experimental techniques have reached a state of development that enables key distribution at MHz rates over distances of 100 km [9–11].”
Differential-phase-shift quantum key distribution (2002, methodology): “The latest DPS-QKD experiment demonstrated the transmission distance over 200 km for a secure key.(19) The key technology in this experiment was a superconducting single-photon detector (SSPD) developed in NIST,(20) which had quite a low dark count (a few cps) and a small time jitter (FWHM = 60 ps),”
High-fidelity transmission of entanglement over a high-loss free-space channel (2009, background): “As the maximal distance for the distribution of quantum entanglement in optical fibres is limited to the orde”
Superconducting nanowire single-photon detectors: physics and applications (2012, methodology): “through result was a high bit rate long distance demonstration at λ = 1550 nm carried out at Stanford University [32] (figure 5(a)).”
Single-photon detectors for optical quantum information applications (2009, background): “SNSPDs have had a major impact in the field of QKD, leading to record transmission distances and bit-rates in optical fibre”
Diamond-based single-photon emitters (2011, background): “While there are other alternatives that are not reliant on this single-photon criterion [134, 135], BB84 and its decoy-state counterpart remain the protocols whose security in realistic implementations has been proven in theory [136].”