High-Speed Measurement-Device-Independent Quantum Key Distribution with Integrated Silicon Photonics
Kejin Wei, Wei Li, Hao Tan, Yang Li, Hao Min, Weijun Zhang, Hao Li, Lixing You, Zhen Wang, Xiao Jiang, Teng‐Yun Chen, Sheng‐Kai Liao, Cheng-Zhi Peng, Feihu Xu, Jian-Wei Pan
Abstract
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 chipbased MDI QKD, benefiting from miniaturization, low-cost manufacture, and compatibility with CMOS microelectronics, is a promising solution for future quantum secure networks.