A visualization of the breakthrough reported by the Heriot-Watt team. Credit: Heriot-Watt University

Researchers at Heriot-Watt University have introduced a prototype quantum network that merges two smaller networks into a single, reconfigurable eight-user system capable of routing — and even teleporting — entanglement on demand.

For many years, physicists have imagined a quantum internet: a global system that provides extremely secure communication and powerful new forms of computing, not through electrical signals but through the strange links that can form between particles of light.

Scientists in Edinburgh now report that they have moved this long-standing idea closer to reality.

A team at Heriot-Watt University has introduced a prototype quantum network that joins two previously separate networks into a single, reconfigurable system supporting eight users. This setup can direct entanglement to different users and can also teleport entanglement whenever needed.

Their results, published in Nature Photonics, establish a higher standard for the scale, versatility and performance that future quantum networks may achieve.

Professor Mehul Malik from Heriot-Watt’s School of Engineering and Physical Sciences said: “Other teams had already demonstrated that you can build a single quantum network and send entanglement to many users at once.

“But this is the first time anyone has managed to link two separate networks together. It doesn’t just distribute entanglement in different ways, it actually lets one network talk to the other. This is a major milestone on the road to a real-world quantum internet.”

Using light’s chaos as a resource

At the heart of the Heriot-Watt prototype, instead of a gleaming quantum chip or custom-engineered device, is a shop-bought optical fiber that costs less than £100.

The team harnessed the scattering behavior of light inside an optical fiber to program their reconfigurable entanglement router.

Dr Natalia Herrera Valencia, lead author of the study, said, “Light tends to ricochet chaotically through the fibers’ hundreds of internal pathways. We turned that chaos into a resource.

The result is a reconfigurable multi-port device that can distribute quantum entanglement between users in multiple patterns, switching between local connections, global connections, and mixed configurations at will.

Crucially, the system can multiplex these channels, meaning it can serve many users simultaneously, rather than one pair at a time. Multiplexing is what allows classical telecoms networks to send vast amounts of data down a single fiber using different wavelengths; here, a similar concept is deployed in the quantum regime.

Most strikingly, the team achieved multiplexed entanglement teleportation, swapping entanglement between four distant users across two channels at once. Previous demonstrations have teleported entanglement, but not across so many simultaneous users in such a flexible architecture.

Dr Natalia Herrera Valencia said: “By shaping the light at the input, we effectively programmed the fiber, transforming its messy internal scattering into a powerful, high-dimensional optical circuit.”

“That lets us route quantum entanglement wherever we want, even teleport it, using this deceptively simple piece of fiber.”

A leap for quantum computing

Professor Malik says the demonstration has exciting implications for quantum computing.

“It’s really exciting. Quantum computing could be world-changing, transforming how we find and develop medicines, create new materials for batteries, and supercharge machine learning.

“A promising current approach to building a large-scale, powerful quantum computer is to interconnect lots of smaller quantum processors.

“Our prototype is a network that can flexibly distribute and swap entanglement among many users, or quantum processors – it could be the breakthrough quantum computing has been waiting for.

“Yes, this is a lab-scale demonstration, but the principle is extendable.”

Reference: “A large-scale reconfigurable multiplexed quantum photonic network” by Natalia Herrera Valencia, Annameng Ma, Suraj Goel, Saroch Leedumrongwatthanakun, Francesco Graffitti, Alessandro Fedrizzi, Will McCutcheon and Mehul Malik, 26 November 2025, Nature Photonics. DOI: 10.1038/s41566-025-01806-x

The work is part of the UK’s £22m Integrated Quantum Networks (IQN) Hub, which aims to build the country’s first large-scale quantum network and help meet the government’s mission to deploy the world’s most advanced quantum network by 2035.

The research team is part of a major research and technology development consortium, the £22M Integrated Quantum Networks (IQN) Hub. Led by Heriot-Watt University, the project is funded by the UKRI Engineering and Physical Sciences Research Council (EPSRC) and brings together the expertise of 14 leading UK universities plus over 50 industrial partners to secure the UK’s leadership in quantum networking.

This research was supported by the UKRI Engineering and Physical Sciences Research Council (EPSRC), the European Research Council (ERC), and the Royal Academy of Engineering. The work was carried out by Heriot-Watt University’s Beyond Binary Quantum Information Lab in collaboration with the Edinburgh Mostly Quantum Lab.

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