Simultaneous Classical Communication and Quantum Key Distribution Based on Plug-and-Play Configuration with an...

Area of Science:

• Quantum Information Science
• Quantum Cryptography
• Optical Communication Systems

Background:

• Simultaneous classical and quantum communication is essential for secure networks.
• Plug-and-play systems simplify quantum key distribution (QKD) by eliminating the need for frequency-locked lasers.
• Existing QKD protocols face challenges with phase noise and key generation rates.

Purpose of the Study:

• To propose and analyze a novel simultaneous classical communication and quantum key distribution (SCCQ) protocol.
• To enhance the performance of plug-and-play QKD systems by incorporating an optical amplifier.
• To improve the secret key rate in practical QKD scenarios.

Main Methods:

• Development of a modified plug-and-play QKD protocol.
• Integration of an optical amplifier into Alice's apparatus.
• Performance analysis through simulations in both asymptotic and finite-size regimes.

Main Results:

• The proposed SCCQ protocol effectively utilizes a single plug-and-play system for multiple functions.
• The modified protocol demonstrates a significant improvement in secret key rate compared to the original version.
• The system exhibits tolerance to phase noise, a common issue in coherent detection.

Conclusions:

• The enhanced plug-and-play SCCQ protocol offers a practical and efficient solution for secure communication.
• The integration of an optical amplifier is a viable strategy for boosting QKD performance.
• This protocol advancement is beneficial for both theoretical and practical QKD applications.