A Silicon Photonic Chip-based System for 2.5-GHz Quantum Key Distribution (QKD)

We have demonstrated a compact, chip-based system for high-speed polarization-encoded QKD, which utilizes advanced silicon photonics technology and operates at a clock rate of 2.5 GHz. Our design enables secure key rates up to 1.018 Mbps at equivalent fiber distance of 100 km in the finite-size regime. The results of the proof-of-principle experiment indicate that this high-speed, chip-based QKD system is a viable, high-performance solution well-suited for upcoming quantum communication applications.