Experimental upstream transmission of continuous variable quantum key distribution access network

TL;DR

This paper demonstrates the first upstream transmission continuous-variable quantum key distribution access network, achieving high secret key rates and extending to multiple users with capacity analysis.

Contribution

It introduces the experimental realization of upstream CV-QKD access networks and analyzes their capacity for multiple users.

Findings

Achieved 390 kbps secret key rate in a two-user network.

Successfully extended to multiple users with capacity analysis.

Performed technical upgrades like phase compensation and data synchronization.

Abstract

Continuous-variable quantum key distribution which can be implemented using only low-cost and off-the-shelf components reveals great potential in the practical large-scale realization. Access network as a modern network necessity, connects multiple end-users to the network backbone. In this work, we demonstrate the first upstream transmission quantum access networks using continuous-variable quantum key distribution. A two-end-user quantum access network is then experimentally realized. Through phase compensation, data synchronization and other technical upgrades, we achieve 390kbps secret key rate of the total network. In addition, we extend the case of two-end-user quantum access network to the case of multiple users, and analyze the network capacity in the case of multiple users by measuring the additive excess noise from different time slots.