Abstract
Current satellite-based quantum key distribution (QKD) is limited to nighttime operations, and the reliance on microwave communication for key distillation leads to significant delays, often spanning several days. These challenges collectively hinder the establishment of a practical global-scale quantum network. Here, by developing a 625-MHz inherently robust decoy-state light source and daytime noise suppression close to the Fourier transform limitation, we achieve QKD covering all the 24 h of the day over a 20-km terrestrial free-space channel, resulting in an average secure key rate of approximately 495 bps. Additionally, bidirectional laser communication is integrated into the QKD transmitter and the ground station to enable real-time key distillation, improving the timeliness from days to real time. This comprehensive verification lays a solid foundation and paves the way for all-day real-time QKD with quantum satellites.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.