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Practical high-dimensional quantum key distribution protocol over deployed multicore fiber
Mujtaba Zahidy1, Domenico Ribezzo2,3,4, Claudia De Lazzari5
1Department of Electrical and Photonics Engineering, Technical University of Denmark, Ørsteds Pl., Kgs. Lyngby, 2800, Denmark.
Nature Communications
|February 23, 2024
Summary
High-dimensional quantum key distribution (QKD) using a 4-dimensional hybrid time-path encoding system achieved secure key generation over a 52-km multicore fiber link. This demonstrates robust QKD implementation in realistic environments using standard telecom equipment.
Area of Science:
- Quantum Information Science
- Cybersecurity
- Optical Communications
Background:
- Quantum key distribution (QKD) offers secure communication based on quantum physics.
- Increasing data rates necessitate higher secret key generation rates in QKD systems.
- High-dimensional QKD (HD-QKD) using path encoding is a promising approach to boost performance.
Purpose of the Study:
- To demonstrate the feasibility of high-dimensional QKD in a realistic, deployed network environment.
- To address the lack of practical demonstrations for HD-QKD systems beyond lab settings.
- To investigate the performance of a 4-dimensional hybrid time-path-encoded QKD system over optical fiber.
Main Methods:
- Implemented a 4-dimensional hybrid time-path-encoded QKD system.
- Utilized a 52-km deployed multicore fiber link (two cores of a 26-km 4-core fiber).
- Combined standard telecommunication equipment with multicore fiber technology.
Main Results:
- Successfully generated secret keys using the 4-dimensional hybrid time-path-encoded QKD system.
- Demonstrated robust QKD performance over the 52-km deployed multicore fiber link.
- Validated the integration of standard telecom equipment with multicore fiber for practical QKD.
Conclusions:
- High-dimensional QKD can be robustly implemented in realistic network conditions.
- The combination of standard telecom equipment and multicore fiber technology is viable for practical QKD.
- This work paves the way for secure, high-rate quantum communication in deployed fiber networks.
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