Continuous-variable quantum key distribution network based on entangled states of optical frequency combs

TL;DR

This paper introduces a novel CVQKD network scheme using entangled optical frequency combs, enabling simultaneous multi-user secret key distribution with potential for scalable quantum communication.

Contribution

It proposes a new CVQKD network based on entangled states of optical frequency combs and analyzes its security and feasibility for short-distance deployment.

Findings

Feasible for short-distance fully connected CVQKD networks

Loss is the main limiting factor for system performance

Provides new ideas for multi-user quantum networks

Abstract

Continuous-variable quantum key distribution (CVQKD) features a high key rate and compatibility with classical optical communication. Developing expandable and efficient CVQKD networks will promote the deployment of large-scale quantum communication networks in the future. This paper proposes a CVQKD network based on the entangled states of an optical frequency comb. This scheme generates Einstein-Podolsky-Rosen entangled states with a frequency comb structure through the process of a type-II optical parametric oscillator. By combining with the scheme of entanglement in the middle, a fully connected CVQKD network capable of distributing secret keys simultaneously can be formed. We analyze the security of the system in the asymptotic case. Simulation results show that under commendable controlling of system loss and noise, the proposed scheme is feasible for deploying a short-distance fully connected CVQKD network. Loss will be the main factor limiting the system's performance. The proposed scheme provides new ideas for a multi-user fully connected CVQKD network.