English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Twin-field (TF) quantum key distribution (QKD) is highly attractive becauseit can beat the fundamental limit of secret key rate for point-to-point QKDwithout quantum repeaters. Many theoretical and experimental studies have shownthe superiority of TFQKD in long-distance communication. All previousexperimental implementations of TFQKD have been done over optical channels withsymmetric losses. But in reality, especially in a network setting, thedistances between users and the middle node could be very different. In thispaper, we perform a first proof-of-principle experimental demonstration ofTFQKD over optical channels with asymmetric losses. We compare two compensationstrategies, that are (1) applying asymmetric signal intensities and (2) addingextra losses, and verify that strategy (1) provides much better key rate.Moreover, the higher the loss, the more key rate enhancement it can achieve. Byapplying asymmetric signal intensities, TFQKD with asymmetric channel lossesnot only surpasses the fundamental limit of key rate of point-to-point QKD for50 dB overall loss, but also has key rate as high as $2.918\times10^{-6}$ for56 dB overall loss. Whereas no keys are obtained with strategy (2) for 56 dBloss. The increased key rate and enlarged distance coverage of TFQKD withasymmetric channel losses guarantee its superiority in long-distance quantumnetworks.

Proof-of-principle experimental demonstration of twin-field quantum key distribution over optical channels with asymmetric losses