Researchers Develop Quantum Memories to Power Long-Distance Networks
- An international team of researchers is developing advanced quantum memories to enable long-range quantum networks, tackling the core challenge of signal loss over extended distances.
- Quantum signals are notoriously fragile and prone to degradation over long distances.
- The AL FreSQO initiative explores how quantum communications can operate using several distinct technologies beyond traditional fibre optics.
An international team of researchers is developing advanced quantum memories to enable long-range quantum networks, tackling the core challenge of signal loss over extended distances. According to the University of Strathclyde, the initiative centers on a three-year, €2 million project known as AL FreSQO, which stands for Atom-Light Free-Space Quantum Optics networking. The project is funded by the European Union under the QuantERA transnational quantum technologies programme and is led by the University of Strathclyde.
Addressing Quantum Signal Loss with Repeater Devices
Quantum signals are notoriously fragile and prone to degradation over long distances. Because these signals cannot be copied or amplified, researchers must deploy alternative methods to extend their operational range. According to Professor Daniel Oi, the lead coordinator of AL FreSQO at Strathclyde, the project uses repeater devices and quantum memories to break long links into shorter segments. These segments are then reconnected through entanglement swapping, allowing quantum information to travel much further across a network. Quantum entanglement serves as a foundational resource for quantum information technologies, enabling secure communications alongside more efficient sensing and computation. Within the AL FreSQO framework, quantum memories act as buffer systems to store quantum information temporarily over long-distance communication links, mitigating signal loss during distribution.
Exploring Alternative Technologies and Transport Applications
The AL FreSQO initiative explores how quantum communications can operate using several distinct technologies beyond traditional fibre optics. According to project documentation, researchers are investigating free-space optical links as an alternative to fibre networks, alongside systems that inter-convert the wavelength of light. This frequency conversion allows telecommunication wavelengths to match frequencies that can more easily interact with quantum systems. These approaches help reduce the reliance on bulky, energy-intensive cryogenic systems commonly required by alternative quantum memory platforms. The flexibility of free-space links opens up potential applications in sectors where traditional optical fibres are impractical. According to project details, AL FreSQO technology could find utility in space missions, aviation, shipping, rail, and haulage transport applications. Professor Oi noted that free-space links are particularly important for satellite communications, while frequency conversion bridges the gap between free-space and fibre networks. As part of the experimental work, Dr Aidan Arnold, a Reader in Physics at Strathclyde, will carry out tests in quantum non-demolition to detect a photon without destroying it.
Collaborative Research Network and Future Goals
The multi-institution project brings together expertise in quantum optics, atomic and solid-state physics, and systems engineering. The University of Strathclyde is collaborating with the Universities of Southampton and Padova, Humboldt University of Berlin, Sabancı University in Istanbul Province, and University of Padova spinout ThinkQuantum. The research aligns with broader regional initiatives, including the Integrated Quantum Networks Quantum Technology Research Hub and the UK National Quantum Strategy, which targets the delivery of advanced quantum networks at scale by 2035. Ultimately, the development of robust quantum memories aims to support secure communications, clock synchronisation, sensing networks, and the eventual realization of the quantum internet while training the next generation of quantum physicists.