Exact analysis of long distance quantum communication over a lossy optical channel using entanglement swapping with a quantum repeater chain and noisy detectors (original) (raw)

We analyze a long-distance entanglement based quantum key distribution (QKD) architecture, which uses multiple linear-optic quantum repeaters, frequency-multiplexed entanglement sources, and classical error correction. We find an exact expression for the secret-key rate, and an analytical characterization of how errors propagate through noisy repeater links, as a function of all loss and noise parameters, when the sources have zero multi-pair emissions, i.e., g2(0)=0g^2(0)=0g2(0)=0. We also present numerical results that show that two-pair-emission rates of a downconversion source has an unworkably poor rate-distance scaling, and show how the performance improves as g2(0)g^2(0)g2(0) of the source decreases. Our analysis of how the entangled state held by the two distant parties evolves through multiple swap operations, can in principle be applied to other repeater architectures as well. The exact results and scaling laws we present, may provide new quantitative insights useful not only for designing lo...

Sign up for access to the world's latest research.

checkGet notified about relevant papers

checkSave papers to use in your research

checkJoin the discussion with peers

checkTrack your impact