When we think about quantum technologies, our thoughts often go to the promises they might one day deliver: computers able to tackle problems beyond today’s machines, communication links secured in new ways, sensors precise enough to measure the world at previously unreachable scales. Those promises are exciting, but they are only the beginning. For quantum technologies to serve research and education in a meaningful way, they need to move beyond the laboratory and meet the real world of infrastructure: fibre, operations, trust, integration, skills, service models and, above all, people.
That was the spirit of the first in-person SIG-Quantum meeting, hosted by CERN on 30 June and 1 July. Colleagues from across the GÉANT community, NRENs, research organisations and industry came together to explore a practical but ambitious question: what role can research and education networks, testbeds and shared expertise play as the quantum landscape develops?
SIG-Quantum, part of the GÉANT Community Programme, was created in June 2025 to give the research and education networking community a place to follow quantum developments, exchange experience, compare national approaches, and identify where collaboration can make a real difference. Its scope is intentionally broad, covering quantum communication, computing, sensing, quantum-safe security, timing and synchronisation, testbeds, skills, standards and emerging service models. That breadth matters. Quantum technologies are beginning to overlap with questions that R&E networks already understand very well: how to build trusted services, connect specialist facilities, support communities across borders, and turn promising experiments into infrastructure that can be operated, shared and improved over time.
CERN was a fitting place for that discussion, as an organisation built around big science, international collaboration and infrastructure pushed to its limits. Quantum may be a new frontier, but many of the challenges around trust, operations, sustainability and working across disciplines are ones this community has been addressing for decades.
A recurring theme throughout the meeting was the distance between quantum’s potential and its practical deployment. There is no shortage of exciting progress, but the R&E networking community needs a clear view of what is ready now, what remains experimental, and where networks can genuinely add value.
A rich ecosystem for a diverse community
Quantum computing, communication, sensing and quantum-safe security each bring different technical challenges. Yet they increasingly rely on many of the same foundations: high-quality connectivity, optical fibre, precise timing, trusted operating environments, specialist expertise, and communities willing to test ideas in realistic conditions. Those foundations are where GÉANT and the NRENs have long played a crucial role, supporting early adopters, building cross-border services, running experimental testbeds, and helping turn ambitious technical requirements into working capability.
The meeting made one point especially clear: quantum technologies will become useful, adoptable and sustainable when they are connected, integrated, trusted and made available to the people and communities that need them.
Computing, communication and sensing
Quantum computing attracted strong interest, with discussions ranging from high-energy physics applications to the way quantum systems may develop alongside classical and high-performance computing. Something that was mentioned more than once is that quantum computing should not be imagined as a single isolated machine sitting in a specialist lab. The more likely future is hybrid.
Quantum processors may work alongside supercomputers, data infrastructure and advanced networks. In time, they may also become distributed and modular, with multiple processors linked through photonic interconnects. For the networking community, that is a significant shift. If quantum computing becomes distributed, networking becomes part of the computing model itself.
Quantum key distribution remains a very visible and mature field, and several organisations are already exploring or deploying it. That makes it a useful starting point because it brings the discussion into contact with real fibre, real key management, real operations and real integration challenges.
But the conversation did not stop at QKD. Participants also looked towards entanglement distribution, early quantum internet concepts, and the possibility of distributed quantum computing as the hardware matures. Quantum sensing added another important dimension. Atomic clocks, magnetometers, gravimeters and gyroscopes are already remarkable instruments. Their wider value, however, may depend on how they are connected: across sites, into data systems, or through fibre networks that allow distributed measurements at a scale no single instrument could reach on its own.
Timing, fibre and an old problem made new
One of the most compelling themes of the meeting brought quantum communication together with timing and synchronisation, an area already central to GÉANT’s work through time and frequency transfer and White Rabbit.
Quantum systems place demanding requirements on timing, optical stability and control. At the same time, research networks already carry classical services, timing signals and data traffic over shared fibre infrastructure. The practical question is how these different uses can coexist.
Work discussed at the meeting on entangled photon pairs sharing optical fibre with White Rabbit signals pointed towards an important possibility: quantum communication may not need to sit entirely apart from existing optical infrastructure. Instead, it may become something woven into it. Getting there will require knowledge of fibre routes, wavelengths, monitoring, operations and user requirements, and it will require people from different communities to work closely together: physicists, timing experts, network engineers, infrastructure operators and service developers.
A community beginning to take shape
The community across research, education, industry and technology is very diverse and this diversity is exactly what SIG-Quantum is for. No single organisation has all the answers, and the field is still moving quickly. The value of the SIG is to create a space where practical questions can be asked early, lessons can be shared openly, and opportunities for joint work can be spotted before effort is duplicated.
The CERN meeting showed that quantum technologies are becoming an infrastructure topic for Europe, not only a subject for specialist laboratories. How should testbeds be connected? How can quantum communication share fibre with existing services? What role should NRENs play in QKD and beyond? How do we build the skills and trust needed for future services? These questions will not be answered in one meeting. But this first in-person SIG-Quantum gathering brought the right people into the same room and gave the conversation a clear direction. SIG-Quantum will continue to provide a place for that conversation to grow, and for the R&E networking community to help shape what comes next.
