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Long-distance quantum key distribution gets real

A ‘twin-field’ repeater-less protocol has enabled an experimental demonstration of secure quantum key distribution over a 511-km long-haul optical fibre link.

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Fig. 1: Twin-field QKD implementation, with the quantum channel shown in black, the synchronization channel in orange and a calibration channel in red.


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Correspondence to Charles C.-W. Lim.

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Lim, C.CW., Wang, C. Long-distance quantum key distribution gets real. Nat. Photon. 15, 554–556 (2021).

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