Stellar calibration of the single-photon receiver for satellite-to-ground quantum key distribution

Abstract Satellite quantum communication is the technology that allows to deploy large-scale quantum networks with a communication range of thousands kilometres We report the ground receiver for downlink quantum key distribution (QKD) with satellite. An optical part of this system including an active tracking loop is mounted on a 600-mm Ritchey-Chretien telescope and permits to distinguish polarization states to perform QKD between ground and satellite. Moreover, a procedure of calibration the receiver using stars with known brightness is presented. Measurements of the photon count rate of stars in the spectral range of 845 nm - 855 nm are performed and compared with an estimate.

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Twin-Field Quantum Key Distribution over 511 km Optical Fiber Linking two Distant Metropolitans

10.21203/rs.3.rs-182908/v1 ◽

2021 ◽

Author(s):

Jiu-Peng Chen ◽

Chi Zhang ◽

Yang Liu ◽

Cong Jiang ◽

Weijun Zhang ◽

...

Keyword(s):

Quantum State ◽

Quantum Key Distribution ◽

Large Scale ◽

Single Photon ◽

Key Distribution ◽

Test System ◽

Long Distance ◽

Quantum Networks ◽

The Cost ◽

Remarkable Progress

Abstract The basic principle of quantum mechanics guarantee the unconditional security of quantum key distribution (QKD) at the cost of inability of amplification of quantum state. As a result, despite remarkable progress in worldwide metropolitan QKD networks over the past decades, long haul fiber QKD network without trustful relay has not been achieved yet. Here, through sending-or-not-sending (SNS) protocol, we complete a twin field QKD (TF-QKD) and distribute secure keys without any trusted repeater over a 511 km long haul fiber trunk linking two distant metropolitans. Our secure key rate is around 3 orders of magnitudes greater than what is expected if the previous QKD field test system over the same length were applied. The efficient quantum-state transmission and stable single-photon interference over such a long distance deployed fiber paves the way to large-scale fiber quantum networks.

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The Performance of Satellite-Based Links for Measurement-Device-Independent Quantum Key Distribution

Entropy ◽

10.3390/e23081010 ◽

2021 ◽

Vol 23 (8) ◽

pp. 1010

Author(s):

Guoqi Huang ◽

Qin Dong ◽

Wei Cui ◽

Rongzhen Jiao

Keyword(s):

Communication Network ◽

Optical Fiber ◽

Quantum Key Distribution ◽

Large Scale ◽

Quantum Communication ◽

Weather Conditions ◽

Key Distribution ◽

Long Distance ◽

Measurement Device ◽

Measurement Device Independent

Measurement-device-independent quantum key distribution (MDI-QKD) protocol has high practical value. Satellite-based links are useful to build long-distance quantum communication network. The model of satellite-based links for MDI-QKD was proposed but it lacks practicality. This work further analyzes the performance of it. First, MDI-QKD and satellite-based links model are introduced. Then considering the operation of the satellite the performance of their combination is studied under different weather conditions. The results may provide important references for combination of optical-fiber-based links on the ground and satellite-based links in space, which is helpful for large-scale quantum communication network.

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