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Field Test of Twin-Field Quantum Key Distribution through Sending-or-Not-Sending over 428 km.
Hui Liu1,2, Cong Jiang3, Hao-Tao Zhu1,2
1Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology ofChina, Hefei, Anhui 230026, People's Republic of China.
Physical Review Letters
|July 9, 2021
Summary
This study demonstrates a field-test of sending-or-not-sending twin-field quantum key distribution (SNS-TF-QKD) over 428 km of deployed fiber. The results achieved a record secure key rate for repeaterless quantum key distribution systems.
Area of Science:
- Quantum Information Science
- Secure Communications Technology
- Experimental Physics
Background:
- Quantum key distribution (QKD) offers information-theoretical security.
- Twin-field QKD (TF-QKD) enhances key rates over long distances.
- Real-world feasibility of TF-QKD remains a challenge.
Purpose of the Study:
- To demonstrate the practical application of TF-QKD outside laboratory settings.
- To assess the performance of TF-QKD in deployed commercial fiber.
- To establish a new distance record for field-tested QKD systems.
Main Methods:
- Utilized sending-or-not-sending twin-field QKD (SNS-TF-QKD) with actively odd parity pairing (AOPP).
- Conducted a field test over 428 km of deployed commercial optical fiber.
- Developed a high-stability system and measured deployed fiber properties.
Main Results:
- Achieved a secure key rate surpassing the limit for repeaterless QKD.
- Established a new distance record for field-tested TF-QKD and fiber-based QKD.
- Successfully demonstrated TF-QKD feasibility in a real-world, long-distance scenario.
Conclusions:
- The field-test validates SNS-TF-QKD for practical, long-distance secure communication.
- This work bridges the gap between laboratory QKD and real-world applications.
- Paves the way for intercity QKD networks with enhanced security.
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