A polarization diversity CV-QKD detection scheme for channels with strong polarization drift

Continuous-variable quantum key distribution (CV-QKD) provides a theoretical unconditionally secure solution to distribute symmetric keys among users connected through a communication channel. However, polarization drift in standard optical fibres can pose a considerable impairment, as it will degrade the efficiency of the coherent detection scheme if not compensated. In this work, we present a novel receiver configuration for CV-QKD that allows for passive polarization drift compensation. The presented results show that our detection system can effectively compensate random polarization drift even in very adverse scenarios.