Simone Cammarata

Continuous-variable quantum key distribution (CV-QKD) has attracted enormous attention in recent years due to its capability to achieve high secret key rates and ease of integration with existing telecom infrastructure. While squeezed-state CV-QKD offers significant advantages over coherent-state protocols, its practicality has remained limited by the bandwidth of traditional squeezers and bulk optical components. In this work, we demonstrate a high-speed squeezed-state CV-QKD system that employs a silicon-photonics integrated transmitter and a photonic–electronic integrated receiver based on a CMOS transimpedance amplifier, together with a broadband single-pass squeezed-light source. Operating at 500 MBaud, our system achieves a finite-size secret key rate of 2.3 Mbit/s over a 10 km fibre channel. This result demonstrates a clear path toward high-speed, scalable, and practical squeezed-state CV-QKD implementations.