Chinese Scientists Set World Record with 1,002km Quantum Key Distribution.

Chinese Scientists Set World Record With 1,002Km Quantum Key Distribution.

Chinese scientists have set a world record by achieving twin-field quantum key distribution (QKD) through a 1,002-kilometer optical fibre, marking a critical step toward a future large-scale quantum network. QKD allows two remote users to generate a shared key for encrypting and decrypting messages. The team from the University of Science and Technology of China, the Jinan Institute of Quantum Technology, and the Shanghai Institute of Microsystem and Information Technology developed dual-band phase estimation and ultra-low noise superconducting nanowire single-photon detectors to suppress system noise.

Chinese Scientists Set World Record in Quantum Key Distribution

Chinese scientists have achieved a world record by successfully implementing twin-field quantum key distribution (QKD) through a 1,002-kilometer optical fibre. This marks a significant step towards developing a large-scale quantum network in the future. QKD is a crucial method in quantum communication, allowing two remote users to generate a shared key known only to them, which is used to encrypt and decrypt messages.

Overcoming Distance Limitations in Quantum Communication

One of the significant challenges in the practical application of QKD is the distance limit. Quantum signals cannot be amplified, and channel transmittance decreases exponentially with distance. Previously, twin-field QKD was demonstrated in lab settings through the spooled fibre up to 830 kilometres. The recent achievement by Chinese scientists has pushed this limit to 1,002 kilometres, with a secure key rate of 0.0034 bits per second.

Innovative Techniques Used to Suppress System Noise

To overcome the distance limitation and achieve the world record, the scientists developed dual-band phase estimation and ultra-low noise superconducting nanowire single-photon detectors. These innovations helped suppress system noise, hindering secure keys’ production in long-distance quantum communication. The study, published in Physical Review Letters, involved scientists from institutions such as the University of Science and Technology of China, the Jinan Institute of Quantum Technology, and the Shanghai Institute of Microsystem and Information Technology.

Feasibility of Twin-Field QKD at Long Distances

The successful implementation of twin-field QKD at a distance of 1,002 kilometres has verified its feasibility for long distances. This breakthrough sheds light on the prospects of long-haul quantum communication and brings us closer to developing a large-scale quantum network.

Implications for the Future of Quantum Communication

The achievement by Chinese scientists in extending the range of twin-field QKD has significant implications for the future of quantum communication. As the distance limitation is overcome, the potential for practical applications of QKD and developing a large-scale quantum network becomes more feasible. This breakthrough marks a critical step towards realizing the full potential of quantum communication technology.

“The study has verified the feasibility of twin-field QKD at a very long distance and shed light on its prospects in long-haul quantum communication,”

University of Science and Technology of China.

Summary

Chinese scientists have set a world record by achieving twin-field quantum key distribution (QKD) through a 1,002-kilometer optical fibre, marking a critical step toward a future large-scale quantum network. The study has verified the feasibility of twin-field QKD at a very long distance and shed light on its prospects in long-haul quantum communication.

  • Chinese scientists have set a world record by achieving twin-field quantum key distribution (QKD) through a 1,002-kilometer optical fibre.
  • QKD is a critical method in quantum communication, allowing two remote users to generate a shared key for encrypting and decrypting messages.
  • The main challenge for QKD is the distance limit, as quantum signals cannot be amplified, and channel transmittance decreases exponentially with distance.
  • Previously, twin-field QKD was demonstrated in lab settings through the spooled fibre of up to 830 kilometres.
  • Scientists from the University of Science and Technology of China, the Jinan Institute of Quantum Technology, and the Shanghai Institute of Microsystem and Information Technology achieved the 1,002-kilometer distance with a secure key rate of 0.0034 bits per second.
  • The researchers developed dual-band phase estimation and ultra-low noise superconducting nanowire single-photon detectors to suppress system noise, which impedes the production of secure keys over long distances.
  • The study verifies the feasibility of twin-field QKD at long distances and sheds light on its prospects in long-haul quantum communication.

Read More: Phys. Rev. Lett. 130, 210801 – Published 25 May 2023