1Department of Modern Physics and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026 2Shanghai Branch, CAS Center for Excellence and Synergetic Innovation Center in Quantum Information and Quantum Physics, Shanghai 201315 3Key Laboratory of Space Active Opto-Electronic Technology, Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai 200083 4Beijing UCAS Space Technology Co., Ltd, Beijing 100190 5National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 6Key Laboratory of Optical engineering, Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209 7Xinjiang Astronomical Observatory, Chinese Academy of Sciences, Urumqi 830011
Abstract：Quantum technology establishes a foundation for secure communication via quantum key distribution (QKD). In the last two decades, the rapid development of QKD makes a global quantum communication network feasible. In order to construct this network, it is economical to consider small-sized and low-cost QKD payloads, which can be assembled on satellites with different sizes, such as space stations. Here we report an experimental demonstration of space-to-ground QKD using a small-sized payload, from Tiangong-2 space lab to Nanshan ground station. The 57.9-kg payload integrates a tracking system, a QKD transmitter along with modules for synchronization, and a laser communication transmitter. In the space lab, a 50 MHz vacuum + weak decoy-state optical source is sent through a reflective telescope with an aperture of 200 mm. On the ground station, a telescope with an aperture of 1200 mm collects the signal photons. A stable and high-transmittance communication channel is set up with a high-precision bidirectional tracking system, a polarization compensation module, and a synchronization system. When the quantum link is successfully established, we obtain a key rate over 100 bps with a communication distance up to 719 km. Together with our recent development of QKD in daylight, the present demonstration paves the way towards a practical satellite-constellation-based global quantum secure network with small-sized QKD payloads.
Schmitt-Manderbach T, Weier H, Fürst M, Ursin R, Tiefenbacher F, Scheidl T, Perdigues J, Sodnik Z, Kurtsiefer C, Rarity J G, Zeilinger A and Weinfurter H 2007 Phys. Rev. Lett.98 010504
[8]
Wang J Y, Yang B, Liao S K, Zhang Li, Shen Q, Hu X F, Wu J C, Yang S J, Jiang H, Tang Y L, Zhong B, Liang H, Liu W Y, Hu Y Hand Huang Y M, Qi B, Ren J G, Pan G S, Yin J, Jia J J, Chen Y A, Chen K, Peng C Z and Pan J W 2013 Nat. Photon.7 387
[9]
Peng C Z, Zhang J, Yang D, Gao W B, Ma H X, Yin H, Zeng H P, Yang T, Wang X B and Pan J W 2007 Phys. Rev. Lett.98 010505
[10]
Liu Y, Chen T Y, Wang J, Cai W Q, Wan X, Chen L K, Wang J H, Liu S B, Liang H, Yang Li, Peng C Z, Chen K, Chen Z B and Pan J W 2010 Opt. Express18 8587
[11]
Korzh B, Lim C C W, Houlmann R, Gisin N, Li M J, Nolan D, Sanguinetti B, Thew R and Zbinden H 2015 Nat. Photon.9 163
Yin H L, Chen T Y, Yu Z W, Liu H, You L X, Zhou Y H, Chen S J, Mao Y Q, Huang M Q, Zhang W J, Chen H, Li M J, Nolan D, Zhou F, Jiang X, Wang Z, Zhang Q, Wang X B and Pan J W 2016 Phys. Rev. Lett.117 190501
[14]
Peev M, Pacher C, Alléaume R, Barreiro C, Bouda J, Boxleitner W, Debuisschert T, Diamanti E, Dianati M, Dynes J F, Fasel S, Fossier S, Fürst M, Gautier J D, Gay O, Gisin N, Grangier P, Happe A, Hasani Y, Hentschel M, Hübel H, Humer G, Länger T, Legré M, Lieger R, Lodewyck J, Lorünser T, Lütkenhaus N, Marhold A, Matyus T, Maurhart O, Monat L, Nauerth S, Page J B, Poppe A, Querasser E, Ribordy G, Robyr S, Salvail L, Sharpe A W, Shields A J, Stucki D, Suda M, Tamas C, Themel T, Thew R T, Thoma Y, Treiber A, Trinkler P, Tualle-Brouri R, Vannel F, Walenta N, Weier H, Weinfurter H, Wimberger I, Yuan Z L, Zbinden H and Zeilinger A 2009 New J. Phys.11 075001
[15]
Sasaki M, Fujiwara M, Ishizuka H, Klaus W, Wakui K, Takeoka M, Miki S, Yamashita T, Wang Z, Tanaka A, Yoshino K, Nambu Y, Takahashi S, Tajima A, Tomita A, Domeki T, Hasegawa T, Sakai Y, Kobayashi H, Asai T, Shimizu K, Tokura T, Tsurumaru T, Matsui M, Honjo T, Tamaki K, Takesue H, Tokura Y, Dynes J F, Dixon A R, Sharpe A W, Yuan Z L, Shields A J, Uchikoga S, Legré M, Robyr S, Trinkler P, Monat L, Page J B, Ribordy G, Poppe A, Allacher A, Maurhart O, Länger T, Peev M and Zeilinger A 2011 Opt. Express19 10387
[16]
Tang Y L, Yin H L, Zhao Q, Liu H, Sun X X, Huang M Q, Zhang W J, Chen S J, Zhang L, You L X, Wang Z, Liu Y, Lu C Y, Jiang X, Ma X, Zhang Q, Chen T Y and Pan J W 2016 Phys. Rev. X 6 011024
Nauerth S, Moll F, Rau M, Fuchs C, Horwath J, Frick S and Weinfurter H 2013 Nat. Photon.7 382
[20]
Yin J, Cao Y, Li Y H, Liao S K, Zhang L, Ren J G, Cai W Q, Liu W Y, Li B, Dai H, Li G B, Lu Q M, Gong Y H, Xu Y, Li S L, Li F Z, Yin Y Y, Jiang Z Q, Li M, Jia J J, Ren G, He D, Zhou Y L, Zhang X X, Wang N, Chang X, Zhu Z C, Liu N L, Chen Y A, Lu C Y, Shu R, Peng C Z, Wang J Y and Pan J W 2017 Science356 1140
[21]
Liao S K, Cai W Q, Liu W Y, Zhang L, Li Y, Ren J G, Yin J, Shen Q, Cao Y, Li Z P, Li F Z, Chen X W, Sun L H, Jia J J, Wu J C, Jiang X J, Wang J F, Huang Y M, Wang Q, Zhou Y L, Deng L, Xi T, Ma L, Hu T, Zhang Q, Chen Y A, Liu N L, Wang X B, Zhu Z C, Lu, C Y, Shu R, Peng C Z, Wang J Y and Pan J W 2017 arXiv:1707.00542
[22]
Ren J G, Xu P, Yong H L, Zhang L, Liao S K, Yin J, Liu W Y, Cai W Q, Yang M, Li L, Yang K X, Han X, Yao Y Q, Li J, Wu H Y, Wan S, Liu L, Liu D Q, Kuang Y W, He Z P, Shang P, Guo C, Zheng R H, Tian K, Zhu Z C, Liu N L, Lu C Y, Shu R, Chen Y A, Peng C Z, Wang J Y and Pan J W 2017 arXiv:1707.00934
Liao S K, Yong H L, Liu C, Shentu G L, Li D D, Lin J, Dai H, Zhao S Q, Li B, Guan J Y, Chen W, Gong Y H, Li Y, Lin Z H, Pan G S, Pelc, J S, Fejer M M, Zhang W Z, Liu W Y, Yin J, Ren J G, Wang X B, Zhang Q, Peng C Z and Pan J W 2017 Nat. Photon.11 509
2017, Vol. 34 
