{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:56:11Z","timestamp":1760151371338,"version":"build-2065373602"},"reference-count":36,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2022,2,27]],"date-time":"2022-02-27T00:00:00Z","timestamp":1645920000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61871234","62001249"],"award-info":[{"award-number":["61871234","62001249"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Open Research Fund of Key Lab of Broadband Wireless Communication and Sensor Network Technology (Nanjing University of Posts and Telecommunications), Ministry of Education","award":["JZNY202104"],"award-info":[{"award-number":["JZNY202104"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>As a variant of the twin-field quantum key distribution (TF-QKD), the sending-or-not twin-field quantum key distribution (SNS TF-QKD) is famous for its higher tolerance of misalignment error, in addition to the capacity of surpassing the rate\u2013distance limit. Importantly, the free-space SNS TF-QKD will guarantee the security of the communications between mobile parties. In the paper, we first discuss the influence of atmospheric turbulence (AT) on the channel transmittance characterized by the probability distribution of the transmission coefficient (PDTC). Then, we present a method called prefixed-threshold real-time selection (P-RTS) to mitigate the interference of AT on the free-space SNS TF-QKD. The simulations of the free-space SNS TF-QKD with and without P-RTS are both given for comparison. The results showed that it is possible to share the secure key by using the free-space SNS TF-QKD. Simultaneously, the P-RTS method can make the free-space SNS TF-QKD achieve better and more stable performance at a short distance.<\/jats:p>","DOI":"10.3390\/e24030344","type":"journal-article","created":{"date-parts":[[2022,2,27]],"date-time":"2022-02-27T20:46:17Z","timestamp":1645994777000},"page":"344","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Prefixed-Threshold Real-Time Selection for Free-Space Sending-or-Not Twin-Field Quantum Key Distribution"],"prefix":"10.3390","volume":"24","author":[{"given":"Yang","family":"Yu","sequence":"first","affiliation":[{"name":"Institute of Signal Processing Transmission, Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210003, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rui","family":"Xu","sequence":"additional","affiliation":[{"name":"Institute of Signal Processing Transmission, Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210003, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Le","family":"Wang","sequence":"additional","affiliation":[{"name":"Institute of Signal Processing Transmission, Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210003, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qianping","family":"Mao","sequence":"additional","affiliation":[{"name":"College of Computer Science and Technology, Nanjing Tech University, Nanjing 211816, China"},{"name":"Key Laboratory of Broadband Wireless Communication and Sensor Network Technology, Ministry of Education, Nanjing 210003, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shengmei","family":"Zhao","sequence":"additional","affiliation":[{"name":"Institute of Signal Processing Transmission, Nanjing University of Posts and Telecommunications (NUPT), Nanjing 210003, China"},{"name":"Key Laboratory of Broadband Wireless Communication and Sensor Network Technology, Ministry of Education, Nanjing 210003, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,27]]},"reference":[{"key":"ref_1","unstructured":"Bennet, C. 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