High-Speed Chip-based Measurement-Device-Independent Quantum Key Distribution with Double-Scanning Method

Photonic integration offers a practical solution for wider deployment of quantum secure communication. Based on carrier-depletion modulators (CDMs) in silicon photonics, we design and fabricate high-speed transmitter chips and demonstrate its capability to implement measurement-device-independent quantum key distribution (MDI-QKD). In the proof-of-concept experiment, the quantum bit error rate (QBER) is as low as 0.85% in Z basis and 25.5% in X basis, respectively. With a double-scanning method, the optimized system shows a key rate per pulse of 1.65 × 10
⁻⁴
over an emulated attenuation of 10 dB (corresponding to 50-km standard fiber) with 80% single photon detection efficiency.