What Is the Quantum Internet and How Does It Work?

A Network Built on Quantum Physics

The internet you use every day moves information as streams of classical bits—ones and zeros racing along fiber-optic cables and radio waves. The quantum internet would do something fundamentally different: it would transmit information encoded in quantum bits (qubits), exploiting the strange rules of quantum mechanics to achieve levels of security and capability that are physically impossible on today's networks.

Unlike science-fiction portrayals of teleportation, nothing physical moves. Instead, the quantum internet transfers quantum states—the delicate information encoded in particles such as photons or electrons—between distant points. The principles that make this possible are quantum entanglement and quantum teleportation.

The Foundation: Quantum Entanglement

Quantum entanglement is the phenomenon at the heart of the quantum internet. When two particles are entangled, their quantum states become interlinked: measuring one particle instantly determines the correlated state of its partner, no matter how far apart they are. Albert Einstein famously called this "spooky action at a distance," and it has been confirmed by decades of experiments.

Entanglement does not allow faster-than-light communication—classical information must still travel by conventional means to interpret results. But it creates a shared, eavesdropper-detectable link between two parties. Because quantum states collapse irreversibly when they are measured or intercepted, any intrusion leaves a detectable fingerprint. This property makes quantum networks inherently tamper-evident.

How Quantum Teleportation Works

Quantum teleportation is the mechanism by which a quantum state is transferred from one location to another without physically sending the particle that carries it. The process requires three things: an entangled pair of particles shared between sender and receiver, the original qubit to be transferred, and a conventional (classical) communication channel to send a small piece of additional data.

The sender performs a measurement that entangles the original qubit with their half of the entangled pair, then transmits the classical outcome to the receiver. The receiver uses this outcome to apply a correction to their entangled particle, perfectly reconstructing the original quantum state. The original qubit is destroyed in the process—no quantum information is duplicated, which is known as the no-cloning theorem.

The Distance Problem: Quantum Repeaters

Ordinary fiber-optic networks use electronic amplifiers to boost signals over long distances. This is impossible in a quantum network: amplifying a qubit would require copying it, which quantum mechanics forbids. Photons carrying quantum states simply get absorbed by the fiber after roughly 100 kilometers.

The solution is the quantum repeater—a specialized node that extends entanglement across long distances without ever copying the qubit. Repeaters work by breaking a long route into shorter segments, establishing entanglement over each segment independently, and then using a process called entanglement swapping to merge those segments into a single end-to-end entangled link. According to Amazon Web Services' quantum technologies team, building reliable quantum repeaters is widely considered the central engineering challenge standing between today's experiments and a functioning global quantum internet.

Recent Milestones

Progress has accelerated in recent years. In late 2024, engineers at Northwestern University demonstrated quantum teleportation over a 30-kilometer fiber-optic cable that was simultaneously carrying 400-gigabit-per-second classical internet traffic—proving that quantum and conventional data can coexist in the same infrastructure.

In early 2025, researchers from the Fraunhofer Institute for Laser Technology in Germany and TNO in Delft activated the first operational quantum internet node in Aachen, establishing regional quantum links between Aachen, Jülich, and Bonn. Separately, teams at the universities of Paderborn and Stuttgart achieved the first quantum teleportation between two different quantum dots—a crucial step toward building scalable repeater networks using semiconductor devices.

What a Quantum Internet Would Enable

The most immediate application is quantum key distribution (QKD): generating encryption keys that are mathematically impossible to intercept without detection, because any eavesdropping disturbs the quantum states and raises an alarm. Governments, banks, and critical infrastructure operators are the most eager early adopters.

Beyond security, a quantum internet would link distant quantum computers into a collective that far exceeds what any single machine could achieve. It would also enable ultra-precise quantum sensing—networks of entangled atomic clocks or gravitational sensors could detect signals too faint for any classical instrument.

How Far Away Is It?

Researchers describe the quantum internet's development in stages, from simple QKD links (already commercially available over short distances) to a fully entanglement-based global network. The European Union's Quantum Internet Initiative targets an operational pan-European quantum network by the late 2030s. A truly global quantum internet, with intercontinental quantum repeater chains, likely lies further in the future—but the foundational breakthroughs are happening now, one entangled photon at a time.