Researchers have successfully demonstrated quantum teleportation of logical operations between separate quantum processors, a breakthrough that pushes the frontier of scalable quantum computing and could lay the foundation for distributed quantum supercomputers and the quantum internet.
Oxford scientists have accomplished what many thought was impossible, so the breakthrough not only pushes the boundaries of computing but also has the potential to transform how we utilize quantum mechanics in technology.
Unlike traditional data transfer that moves information by sending bits along wires, quantum teleportation leverages entanglement, a phenomenon in which two quantum particles remain linked such that the state of one instantly affects the other, even across distance. In this experiment by researchers at the University of Oxford’s Department of Physics, two independently housed quantum processors were connected through a photonic network interface that used light (photons) to establish entanglement.
“In our study, we use quantum teleportation to create interactions between these distant systems,” said Dougal Main, a Physics graduate student and part of the research team, in a statement. “By carefully tailoring these interactions, we can perform logical quantum gates — the fundamental operations of quantum computing — between qubits housed in separate quantum computers… This breakthrough enables us to effectively ‘wire together’ distinct quantum processors into a single, fully connected quantum computer… By interconnecting the modules using photonic links, the system gains valuable flexibility, allowing modules to be upgraded or swapped out without disrupting the entire architecture.”
The team’s work differs from earlier demonstrations of quantum teleportation, which transferred the state of individual qubits. Here, the breakthrough involved teleporting logical gate operations, the fundamental computational functions that make up quantum algorithms, between processors. This effectively allows physically separate quantum computers to operate together as a single, modular quantum system.
To validate their approach, researchers successfully executed Grover’s search algorithm, a quantum routine known for its theoretical speed advantages over classical search algorithms, across the linked processors. This confirmed that the teleported operations preserved the quantum computational advantages while enabling distributed execution.
The researchers linked machines separated by several feet and emphasized the potential of photonic links to overcome qubit scalability hurdles that have constrained larger systems.
Experts describe this modular, “networked” approach as akin to how classical supercomputers combine many smaller nodes to achieve high performance. Here, quantum teleportation may serve as the connective tissue that scales quantum computing without requiring prohibitively large monolithic processors.
“Our experiment demonstrates that network-distributed quantum information processing is feasible with current technology,” principal investigator and Oxford physics professor David Lucas expressed his views about the experiment… Scaling up quantum computers remains a formidable technical challenge that will likely require new physics insights as well as intensive engineering effort over the coming years. “
Beyond computing power, the demonstration accelerates progress toward a quantum internet, a future communications infrastructure that uses quantum entanglement to transmit information with theoretically unbreakable security and instantaneous coordination. Researchers believe that teleportation protocols linking distributed processors could form the basis of such networks.
Despite the challenges of building larger quantum computers, scientists are still facing hurdles in making them practical tools for solving real-world problems. Scientists caution that numerous obstacles remain. Environmental noise, error rates, and decoherence, the loss of quantum state integrity, still limit practical scaling, and maintaining entanglement across longer distances or heterogeneous hardware will require further innovation.
However, there’s a sense of optimism among researchers that one day, quantum computing systems could perform calculations in mere hours that would take today’s supercomputers years to complete.
The research is published in Nature.