Global Scale Quantum Networking: Accelerating the feasibility, scalability, and maturity of networked quantum technologies

There is a concerted worldwide effort to develop near-term networked quantum technologies (NQTs) to enable improved performances in imaging, sensing, computing, and communications. Recent landmark results from China’s quantum satellite Micius have demonstrated key milestones to increase the span of NQTs. A succession of international initiatives has also been launched to develop quantum networking infrastructure, such as the European Quantum Communication Infrastructure initiative. However, developing quantum networks (QNs) still has to overcome open challenges in feasibility, scalability, and maturity. This research project aims to directly address these open challenges. I will improve security analyses and develop two novel quantum key distribution protocols with improved loss tolerance and enhanced integration between terrestrial and satellite networks. This will enable longer-range quantum communications than existing methods. Numerical simulations and experimental demonstrations will be performed to validate this advantage. I will then develop an open-source numerical framework, based on a conceptually simple bi-graph, to inform on QN topologies that optimise entanglement distribution rates. This framework goes beyond specific network topologies considered in existing research and can be applied to any communication protocol. As a forward-looking application, I will explore the performance of distributed quantum computing. By developing insights into the optimal design of QNs that enhance the fidelity of non-local quantum gates, this work would help identify parameter regimes for quantum devices to support the operation of large-scale quantum computing. I will present a roadmap toward implementation, which may aid ongoing experimental and engineering efforts to advance NQTs. The GSQNET project is therefore a timely project that will support the development of NQTs in Europe through fundamental research and translational studies.