Quantum Network Links Two Systems in Breakthrough

Researchers from the School of Engineering and Physical Sciences at Heriot-Watt University have unveiled a prototype quantum network capable of linking two smaller networks into one reconfigurable, eight-user system. This demonstration, recently reported in Nature Photonics, establishes a new benchmark for large, flexible quantum networks by enabling the routing and on-demand teleportation of entanglement. Utilizing a shop-bought optical fibre costing less than £100, the team harnessed light’s chaotic scattering to program a reconfigurable entanglement router, achieving multiplexed entanglement teleportation across four distant users simultaneously – a capability not previously demonstrated in such a flexible architecture.

Prototype Quantum Network Demonstration

Heriot-Watt scientists have demonstrated a prototype quantum network by successfully linking two smaller networks into a single, reconfigurable eight-user system. This network is capable of routing and teleporting entanglement on demand, representing a significant step towards a practical quantum internet. The demonstration, published in Nature Photonics, establishes a new benchmark for the size, flexibility, and capability of quantum networks. This advancement could be key to unlocking the potential of quantum computing by enabling interconnection of multiple smaller processors.

At the heart of the prototype is a surprisingly affordable component: a shop-bought optical fibre costing less than £100. Researchers harnessed the chaotic scattering of light within the fibre to create a programmable entanglement router. This allowed them to distribute quantum entanglement between users in various patterns – local, global, or mixed – and crucially, to multiplex channels, serving multiple users simultaneously. The team achieved multiplexed entanglement teleportation between four users across two channels, a feat not previously demonstrated with such flexibility.

This work is part of the UK’s £22m Integrated Quantum Networks (IQN) Hub, aiming to establish a large-scale quantum network by 2035. The Hub, funded by the Engineering and Physical Sciences Research Council (EPSRC), involves 14 universities and over 50 industrial partners. Professor Malik suggests this prototype could be the breakthrough quantum computing needs, enabling interconnection of smaller quantum processors, and potentially revolutionizing fields like medicine, materials science, and machine learning.

Harnessing Light for Entanglement Routing

Heriot-Watt scientists have created a prototype quantum network linking two smaller networks, achieving a reconfigurable, eight-user system. This network is capable of routing and teleporting entanglement on demand—a crucial step towards a quantum internet. The demonstration, published in Nature Photonics, marks a new benchmark for large, flexible quantum networks, going beyond simply distributing entanglement to enabling communication between separate networks. This breakthrough could be pivotal for advancing quantum computing capabilities.

At the heart of this prototype is a commercially available optical fiber costing less than £100. Researchers harnessed the chaotic scattering of light within the fiber to program a reconfigurable entanglement router. By shaping the input light, they transformed the fiber’s internal chaos into a high-dimensional optical circuit, enabling flexible routing of quantum entanglement. Critically, the system supports multiplexing, allowing it to serve multiple users simultaneously – a key feature mirroring classical telecom networks.

This system achieved multiplexed entanglement teleportation, successfully swapping entanglement between four users across two channels concurrently. This surpasses previous demonstrations and demonstrates a flexible architecture. Professor Malik suggests this network could interconnect smaller quantum processors, potentially unlocking a powerful, large-scale quantum computer. The work is supported by the UK’s £22m Integrated Quantum Networks (IQN) Hub, aiming for a world-leading quantum network by 2035.

Implications for Quantum Computing

This prototype quantum network represents a potential breakthrough for quantum computing, as it demonstrates a flexible system for distributing and swapping entanglement among many users or quantum processors. Professor Malik suggests interconnecting numerous smaller quantum processors is a promising approach to building a large-scale, powerful computer, and this network could be key to realizing that vision. The system’s ability to flexibly connect and share entanglement is a significant advancement over previous demonstrations.

The Heriot-Watt prototype achieved multiplexed entanglement teleportation, successfully swapping entanglement between four distant users across two channels simultaneously. This is a step beyond previous teleportation demonstrations, which did not involve as many users or a flexible architecture. Utilizing a shop-bought optical fibre—costing less than £100—the team harnessed light’s chaotic scattering to create a reconfigurable multi-port device capable of distributing entanglement in various patterns.

This research is part of the UK’s £22m Integrated Quantum Networks (IQN) Hub, aiming to establish a large-scale quantum network by 2035. The project, funded by the Engineering and Physical Sciences Research Council (EPSRC), involves collaboration between 14 universities and over 50 industrial partners. The Hub’s work supports the UK Government’s mission to deploy the world’s most advanced quantum network at scale, positioning the nation as a leader in quantum networking.