Terahertz Continuous-Variable Measurement-Device-Independent Quantum key Distribution with Photon Subtraction in Inter-Satellite Links Communication

Quantum communication in the terahertz (THz) band is an important technology for next-generation high-capacity wireless networks, and inter-satellite quantum key distribution in low-earth-orbit (LEO) is one of the critical research directions. A terahertz continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) with photon subtraction for secure inter-satellite link communications, derive the security bounds for the protocol, is proposed and the performance of the inter-satellite link in the asymptotic limit, in addition to obtaining a tighter protocol bound by considering finite size effects, is evaluated. Through simulation calculations, the method can maintain high secret key rates and robust security, which will provide a more effective way to build future quantum networks.