Oxford scientists link quantum computers via teleportation

This achievement, detailed in a new study published in Nature, marks the first demonstration of distributed quantum computing, potentially overcoming the scalability challenge that has long hindered quantum technology.

Quantum computing holds the promise of tackling problems far beyond the reach of classical computers, but building a practical quantum system requires handling millions of qubits. A single device of this scale would be prohibitively large and complex. The Oxford-led research team has proposed and demonstrated an alternative approach: linking smaller quantum devices via a photonic network interface to create a scalable quantum computing architecture.

The team’s method involves modular quantum processors, each containing a small number of trapped-ion qubits – atomic-scale carriers of quantum information. These modules are connected via optical fibres, using photons rather than electrical signals to transmit quantum data. By entangling qubits across modules, the researchers enabled quantum logic operations to be executed through a process known as quantum teleportation.

Crucially, while previous research has focused on teleporting quantum states, this study is the first to demonstrate the teleportation of logical quantum gates – the fundamental building blocks of quantum algorithms – between distinct processors. This capability paves the way for distributed quantum computing, akin to how classical supercomputers link multiple processing units to enhance performance.

To validate their approach, the researchers successfully executed Grover’s search algorithm, a quantum method that significantly speeds up data searches compared to classical computing. This demonstration underscores the potential of a distributed quantum architecture to extend computational power beyond the limitations of a single machine.

Professor David Lucas, principal investigator and lead scientist for the UK Quantum Computing and Simulation Hub, emphasised the significance of the achievement: “Our experiment demonstrates that network-distributed quantum information processing is feasible with today’s technology. Scaling up quantum computers remains a significant challenge, but our work shows a promising path forward.”

The findings bring the prospect of a ‘quantum Internet’ closer to reality, where distant quantum processors could form an ultra-secure network for computation, communication, and sensing applications. As quantum technologies continue to develop, distributed architectures may hold the key to realising practical, high-performance quantum computing.

This research was supported by UKRI EPSRC through the UK Quantum Computing and Simulation Hub, part of the UK National Quantum Technologies Programme.