Performance Improvement for Discretely Modulated Continuous-Variable Measurement-Device-Independent Quantum Key...

Area of Science:

• Quantum Information Science
• Quantum Cryptography
• Quantum Communication Networks

Background:

• The modulation scheme is critical for continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD).
• Discrepancies in modulation between transmitters, especially with discrete formats (e.g., four-state, eight-state), degrade CV-MDI-QKD performance and security.
• Investigating imbalanced modulation effects is crucial for practical CV-MDI-QKD deployment.

Purpose of the Study:

• To analyze the impact of imbalanced transmitter modulation on CV-MDI-QKD security.
• To explore protocol performance under symmetric and asymmetric distance configurations.
• To develop a practical and cost-effective modulation strategy for enhanced CV-MDI-QKD.

Main Methods:

• Utilized imbalanced discrete modulation maps for CV-MDI-QKD.
• Employed numerical convex optimization techniques for analysis and enhancement.
• Simulated protocol performance under various distance scenarios.

Main Results:

• The proposed CV-MDI-QKD protocol with imbalanced modulation shows significantly higher secret key rates.
• Achieved an approximate 77.77% increase in secret key rate and a 24.3% boost in maximum transmission distance compared to the original protocol.
• Demonstrated enhanced security and extended reach in both symmetric and asymmetric distance setups.

Conclusions:

• Imbalanced discrete modulation offers a practical and simplified approach to boost CV-MDI-QKD performance.
• The method enhances secret key rates and transmission distances without requiring modifications to existing experimental setups.
• This approach facilitates cost-effective and secure quantum communication networks in real-world applications.