Optimized quantum entanglement network enabled by a state-multiplexing quantum light source

TL;DR

This paper presents a novel wavelength division multiplexing quantum network using a state-multiplexing light source, significantly enhancing scalability and efficiency for quantum communication among multiple users.

Contribution

It introduces a dual-pump configuration for generating multiplexed entangled photon pairs, demonstrating a scalable, resource-efficient quantum network with minimized infrastructure.

Findings

Successfully generated multiplexed photon pairs at multiple wavelengths.

Established a fully connected network among four users with six channels.

Achieved a secure key rate of 1946.9 bps using BBM92 protocol.

Abstract

A fully connected quantum network with a wavelength division multiplexing architecture plays an increasingly pivotal role in quantum information technology. With such architecture, an entanglement-based network has been demonstrated in which an entangled photon-pair source distributes quantum entanglement resources to many users. Despite these remarkable advances, the scalability of the architecture could be constrained by the finite spectrum resource, where O(N^2)wavelength channels are needed to connect N users, thus impeding further progress in real-world scenarios. Here, we propose an optimized scheme for the wavelength division multiplexing entanglement-based network using a state-multiplexing quantum light source. With a dual-pump configuration, the feasibility of our approach is demonstrated by generating state-multiplexing photon pairs at multiple wavelength channels with a silicon nitride microring resonator chip. In our demonstration, we establish a fully connected graph between four users with six wavelength channels - saving half of which without sacrificing functionality and performance of the secure communication. A total asymptotic secure key rate of 1946.9 bps is obtained by performing the BBM92 protocol with the distributed state. The network topology of our method has great potential for developing a scalable quantum network with significantly minimized infrastructure requirements.