A low-complexity heterodyne CV-QKD architecture

In contrast to the more prominent discrete-variable quantum key distribution (DV-QKD), which requires specialized hardware like single-photon detectors, the continuous-variable version (CV-QKD) promises low-cost and high-performance implementations by leveraging mature telecommunication technology. In this paper we demonstrate a simplified CV-QKD architecture based on analog frontends and digitizers for mobile communication systems and standard optical components. The high-fidelity, software-defined receiver and transmitter allow us to shift complexity from the analog to the digital domain, thus simplifying the system, improving robustness and paving the way for a low-cost implementation.