Enhancing the performance of entanglement-based WDM-QKD

Area of Science:

• Quantum Information Science
• Optical Communication Systems
• Network Security

Background:

• Entanglement-based quantum key distribution (EB-QKD) is crucial for secure quantum networks.
• Integrating EB-QKD with existing fiber infrastructure via wavelength-division multiplexing (WDM) is essential but limited by classical system noise.
• Existing EB-WDM-QKD systems face performance constraints due to inherent noise from classical channels.

Purpose of the Study:

• To improve the performance and extend the transmission distance of EB-WDM-QKD systems.
• To address the limitations imposed by classical channel noise in integrated quantum communication networks.
• To develop practical strategies for enhancing the robustness of quantum key distribution over shared fiber infrastructure.

Main Methods:

• Proposed an improved EB-WDM-QKD scheme incorporating optical amplifiers to boost signal strength.
• Implemented advantage distillation (AD) for scenarios with non-adjustable classical channel power.
• Optimized classical subsystem configuration and quantum subsystem post-processing.

Main Results:

• Achieved a transmission distance increase of over 70 km in fixed classical received power scenarios using optical amplifiers.
• Extended transmission distance by more than 50 km using AD for non-adjustable launch power conditions.
• Demonstrated significant performance enhancement for EB-WDM-QKD systems.

Conclusions:

• Optical amplifiers and advantage distillation effectively enhance EB-WDM-QKD performance and transmission distance.
• Optimizing classical and quantum subsystems provides a viable path for robust quantum communication.
• The proposed methods offer potential for broader application in various WDM-QKD systems, advancing quantum network development.