Researchers at Oxford University have successfully demonstrated distributed quantum computing for the first time, linking two separate quantum processors into a fully connected system. This breakthrough, published in Nature, brings the development of powerful quantum supercomputers closer, enabling them to tackle problems beyond the reach of conventional computing.
One of the biggest challenges in quantum computing is scalability. To perform groundbreaking computations, quantum computers need to process millions of qubits, but fitting such an extensive system into a single device is impractical due to size and cooling constraints. The new approach solves this by connecting smaller quantum modules via optical fiber links, allowing computations to be distributed across a network without a limit on the number of processors.
The system is based on trapped-ion qubit modules, which transmit data using photons instead of electrical signals. This enables entanglement between qubits across separate modules, allowing quantum operations to be performed using quantum teleportation. While quantum teleportation of states has been achieved before, this is the first time that logical quantum operations have been teleported between different processors, paving the way for a future quantum internet.
This technology mirrors the architecture of traditional supercomputers, which connect multiple processors to create a more powerful system. To prove the effectiveness of the method, researchers successfully ran Grover’s algorithm, a quantum search algorithm that finds information in unstructured databases much faster than classical computers. This demonstrates that a distributed approach enhances quantum computing power, making it possible to perform tasks that today's supercomputers would require years to complete.
Lead researcher Professor David Lucas emphasized that the experiment confirms the feasibility of network-based quantum computing with existing technology. However, scaling up quantum computers remains a complex challenge that will require new physics insights and engineering breakthroughs. The study was supported by the UK Quantum Computing and Simulation Hub, part of the UK National Quantum Technologies Programme.