The classical internet reshaped the modern world by collapsing distance, carrying email across continents in seconds, all done using ones and zeros of ordinary classical bits. That infrastructure is not going anywhere, and the emerging phenomenon known as the quantum internet beginning to take shape in laboratories is not built to replace it, nor to load pages faster or retire the fibre already in the ground. The quantum internet’s purpose is narrower, and put simply its job is to carry something the classical network physically cannot: the fragile quantum state of individual particles.

The network's value lies in what becomes possible once quantum machines are linked. A quantum internet connects processors and sensors using quantum bits (qubits), the basic building blocks of quantum computers, in this case usually photons, preserving quantum mechanics, specifically superposition and entanglement, across distance. It is best understood as a new category of infrastructure alongside the classical internet, built to distribute unbreakable encryption, to cluster separate quantum computers into a single more capable machine, and to link precision instruments into one shared network.

The Physics Beneath The Quantum Network

Everything rests on one property, entanglement, which earned Alain Aspect, John F. Clauser, and Anton Zeilinger, the 2022 Nobel Prize in Physics. Two particles can be prepared so that neither holds a settled value alone. As the instant one is read the other's is fixed to match. That shared link, which Einstein dismissed as “spooky action at a distance”, is the network's raw material, and because a qubit cannot be copied or sent intact, its state moves only by measuring it against that link and sending an ordinary message, so nothing ever outruns light, as some may question.

The second pillar is the no-cloning theorem, which forbids making a perfect copy of an unknown quantum state. On the classical internet a hacker can copy a data packet unnoticed, whereas here any attempt to read a qubit disturbs it, destroying the information and exposing the intruder. This underpins quantum key distribution, or QKD, in which two parties share a secret key that physics prevents an eavesdropper from silently intercepting. Several companies, such as Toshiba, have already commercialised this, and banks and governments treat QKD as the first commercial rung of the quantum internet.

A Quantum Relay With A Different Runner On Each Leg

No single nation or company leads the quantum internet, because it is not one technology but a chain of them, and the lead changes hands like a relay with a different runner on each leg. China runs well ahead at the deployment-ready end, its programme tied largely to Pan Jianwei's group at the University of Science and Technology of China (USTC), which produced the roughly 2,000 km backbone between Beijing and Shanghai, placed into service in 2017, and Micius, the world’s first dedicated quantum science satellite, launched in 2016. That early backbone has since expanded into an operational national QKD network spanning more than 10,000km. This is leadership in the part that already works, though arguably the least transformative, since key distribution secures communication without linking quantum computers.

The harder and more futuristic end is more evenly contested, although Europe, and above all the Netherlands, punches far above its weight. In 2021, QuTech in Delft built the first genuine multi-node network connecting separate quantum processors, and in 2024 it ran entanglement across 25 km of deployed fibre between Delft and The Hague, the branch that could one day network machines, not merely secure messages. The United Kingdom holds a niche of its own, with the University of York back in 2023, tested quantum communications over the 224 km Rockabill submarine cable beneath the Irish Sea, then the longest deployed submarine fibre span used for such an experiment. 

The commercial and component layer is arguably most concentrated in the United States. Cisco is positioning itself as the intended interconnect and orchestration layer provider, demonstrating metro-scale entanglement swapping using 17.6 km spans of deployed commercial fibre in New York, with Qunnect in early 2026, the same Qunnect that commercialised the first room-temperature quantum memory in 2021. In July 2026 a Northwestern group went a step further, distributing entanglement across 24.4 km of installed fibre between Evanston and downtown Chicago while that same strand carried live commercial internet traffic, holding fidelity above 94% and suggesting the quantum internet may not need fibre of its own. Leadership is thus distributed across these three geographical centres, each holding a different link in the same chain.

The Weak Link In The Chain

The same no-cloning rule that makes the network secure is also one of its central engineering obstacles. A classical signal can be copied and amplified along the way, whereas a quantum one cannot, and over distance it fades into noise. The device meant to solve this, the quantum repeater, is therefore one of the primary bottlenecks between today's demonstrations and a continental network. It is effectively a small, special-purpose quantum computer at each waypoint that must generate entanglement across lossy fibre, hold that state in a quantum memory until the neighbouring link succeeds, and fuse two short links into one through “entanglement swapping”. No platform yet performs all three well, and the memory is usually the first to break.

Whoever masters memory-based repeaters at telecom wavelengths will reshuffle the global quantum internet race to a great extent. One of the most integrated demonstrations came from a Harvard group with the AWS Center for Quantum Networking, which in 2024 entangled two diamond-based memory nodes over 35 km of deployed fibre in the Boston area and held the link for up to one second, albeit with cryogenic cooling and demanding nanofabrication. An Innsbruck experiment had already come closer to the repeater operation itself, establishing entanglement across two 25 kilometre fibre spools and swapping it across the combined 50 kilometres. That said, until complete repeaters can generate, store, and swap entanglement reliably across multiple field links at useful rates, the grander quantum internet remains a research programme, however impressive the individual demonstrations become.

What A Working Network Would Unlock

The nearest prize is also the most concrete, security guaranteed by physics rather than mathematics. Today's encryption holds only while no adversary commands the computing power to break the underlying maths, a protection that a powerful-enough quantum computer eventually voids, which is why some states and firms already harvest encrypted traffic to decrypt later. A quantum internet closes that door by making any interception physically leave a mark, so that certain kinds of trust would no longer depend on anyone proving trustworthy.

Two further prizes stand out, both further from market than the first. The relatively nearer is blind quantum computing, in which a remote machine solves a client's problem without ever learning the data, the question, or the answer, possible on the classical cloud today using homomorphic encryption, which processes data while it remains encrypted, though often slow and at considerable computational cost. Blind quantum computing, highlighted in QED-C’s Networking Applications report as approximately 10 years away, could theoretically offer stronger privacy that does not depend on any limit to an attacker’s computing power. This enhanced privacy  would be highly valuable in fields such as medicine and finance. The other prize is better understood as enhanced sensing. By distributing entanglement, a quantum network could allow distant instruments to behave as one, so that linked atomic clocks could gauge a mountain's height more accurately by detecting how gravity alters the passage of time, while linked telescopes could one day combine their observations into a virtual aperture spanning continents. A widely cited 2018 paper in Science by Stephanie Wehner and colleagues at QuTech frames the whole endeavour as a ladder of stages, with today's systems near the bottom.

Seen whole, the quantum internet is a relay whose lead passes from stage to stage, with China on the deployed encryption legs, American and European firms on components and software, and the decisive stage of memory and repeaters still confined to the laboratory. That structure is of strategic importance, because a chain is only as strong as its weakest link, and advances only as fast as its slowest. The nation or company that finally forges the missing link, the working long-range repeater, will likely decide when the whole network comes alive.