High-Speed Measurement-Device-Independent Quantum Key Distribution with Integrated Silicon Photonics

• Main Authors: Kejin Wei, Wei Li, Hao Tan, Yang Li, Hao Min, Wei-Jun Zhang, Hao Li, Lixing You, Zhen Wang, Xiao Jiang, Teng-Yun Chen, Sheng-Kai Liao, Cheng-Zhi Peng, Feihu Xu, Jian-Wei Pan
• Format: Article
• Language: English
• Published: American Physical Society 2020-08-01
• Series: Physical Review X
• Online Access: http://doi.org/10.1103/PhysRevX.10.031030

Measurement-device-independent quantum key distribution (MDI QKD) removes all detector side channels and enables secure QKD with an untrusted relay. It is suitable for building a star-type quantum access network, where the complicated and expensive measurement devices are placed in the central untrusted relay and each user requires only a low-cost transmitter, such as an integrated photonic chip. Here, we experimentally demonstrate a 1.25-GHz silicon photonic chip-based MDI QKD system using polarization encoding. The photonic chip transmitters integrate the necessary encoding components for a standard QKD source. We implement random modulations of polarization states and decoy intensities, and demonstrate a finite-key secret rate of 31  bit/s over 36-dB channel loss (or 180-km standard fiber). This key rate is higher than state-of-the-art MDI QKD experiments. The results show that silicon photonic chip-based MDI QKD, benefiting from miniaturization, low-cost manufacture, and compatibility with CMOS microelectronics, is a promising solution for future quantum secure networks.