Abstract
We address feasibility of continuous-variable quantum key distribution using bright multimode coherent states of light and homodyne detection. We experimentally verify the possibility to properly select signal modes by matching them with the local oscillator and this way to decrease the quadrature noise concerned with unmatched bright modes. We apply the results to theoretically predict the performance of continuous-variable quantum key distribution scheme using multimode coherent states in scenarios where modulation is applied either to all the modes or only to the matched ones, and confirm that the protocol is feasible at high overall brightness. Our results open the pathway towards full-scale implementation of quantum key distribution using bright light, thus bringing quantum communication closer to classical optics.
Highlights
Quantum key distribution (QKD) is well known to be a practical application of quantum information science
In a proof-of-principle experiment we have demonstrated the homodyne detection of bright multimode coherent light with some of the modes not matching the local oscillator
These tests, along with the numerical modeling, confirm the feasibility of quantum key distribution with macroscopically bright coherent states, which can be fully implemented in real optical channels
Summary
Quantum key distribution (QKD) is well known to be a practical application of quantum information science. The LO should match the signal modes despite the joint measurement Even in such simplified scenario we experimentally confirm the possibility to select signal modes and reduce the noise arising from the mode mismatch by increasing the brightness of the local oscillator beam, serving as a phase reference for the homodyne detection. This is important for QKD because the unmatched modes can be tampered with by a potential eavesdropper. Using the obtained results we predict the performance of CV QKD with bright multimode coherent light and confirm its feasibility
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
