Quantum optical switches, repeaters, and satellite infrastructure are the technologies most likely to unlock commercially viable quantum networking, according to a new roadmap from the Quantum Economic Development Consortium (QED-C).

Developed with the National Science Foundation (NSF) Center for Quantum Networks and industry partners, the report evaluates 10 commercially significant quantum networking applications. It concludes that advances in each of those three technologies would enable nine of the 10 use cases assessed.

Together, the findings suggest that extending quantum networks beyond today's short-distance, point-to-point links will require significant advances in the infrastructure used to route and distribute quantum information over larger networks.

"Quantum networking is still in its early stages of development, but it has the potential to extend the value of quantum computing, sensing, and security," QED-C Executive Director Celia Merzbacher explained. "This roadmap is intended to show the various capabilities and technologies in which progress is needed and where targeted investment could have the greatest impact."

The report identifies 10 applications spanning network security, networked quantum computing, and distributed sensing, including quantum key distribution (QKD), blind quantum computing, clustered and distributed quantum computing, and distributed quantum sensing.

According to the analysis, today's quantum networks are sufficiently mature to support QKD and distributed quantum sensing, and only over relatively short point-to-point links. Wider-area quantum networks will require advances in repeaters, satellite infrastructure, and quantum-compatible optical switching.

The roadmap identifies transmission rate, distance, fidelity, and synchronization as the principal performance bottlenecks limiting broader deployment. It also identifies quantum light sources and light-matter interfaces as enabling technologies for eight of the 10 applications examined. Those capabilities will be needed to improve both the scale and reliability of future quantum networks.

One notable conclusion is that clustered quantum computing, such as networking processors within a data center, could become commercially viable in about five years, while long-distance distributed quantum computing remains roughly a decade away due to larger technology gaps.

Saikat Guha, co-director of the NSF Center for Quantum Networks, said the roadmap provides "a foundation for aligning research with high-impact use cases and informing the technical roadmaps needed to accelerate technology transition."

The roadmap was developed with contributions from industry, academia, government, and national laboratories, including IonQ, L3Harris Technologies, Aliro Quantum, Horizon Quantum, the University of Arizona, Argonne National Laboratory, and the National Institute of Standards and Technology (NIST).