Historical breakthrough: scientists have created the first three-node quantum network using individual atoms
Quantum computing takes another giant leap forward. A team of researchers from Duke University and IonQ has announced the creation of the world's first fully distributed three-node quantum network, operating on the basis of individual atomic qubits. This achievement marks a critical stage on the path to a practical quantum internet.
In the experiment, specialists managed to form a so-called three-party entangled state (Greenberger–Horne–Zeilinger, or GHZ) between three remote quantum nodes. These nodes were connected to each other via photonic channels, enabling quantum correlation independent of distance.
Why This Changes the Game
Quantum entanglement is a phenomenon where a change in the state of one particle instantly reflects on the state of another, regardless of whether they are in the same laboratory or on different continents. Until now, scientists have successfully demonstrated entanglement between two nodes, but creating a stable three-party state on individual atoms represents a fundamentally new level of complexity.
The main problem with modern quantum computers is scaling. Building a single giant processor without errors is practically impossible due to the physical limitations of the equipment. This is why the industry is increasingly moving toward a modular architecture: instead of one monolithic device, a network of many quantum "servers" connected by photons is created. This approach mirrors the evolution of the classical internet, where computing resources are distributed across thousands of data centers.
Numbers and Evidence
During the experiment, researchers achieved a fidelity of the entangled state at the level of 84–88%. This is a very high indicator for a three-node system. Moreover, scientists closed the so-called "detection loophole" for a fully distributed multi-component quantum state for the first time. Additionally, the results confirmed the violation of the Mermin inequality — one of the key tests that unequivocally proves the presence of genuine quantum correlations, rather than random coincidences.
Looking to the Future
This work continues a series of IonQ studies in the field of photonic connections. Previously, the company had already demonstrated entanglement between two remote ion systems, but now the architecture has been expanded to three full-fledged nodes. Although the technology is still far from commercial application, such experiments are fundamental building blocks for future distributed quantum computers, secure communication networks, and ultimately, the quantum internet.
Expert Opinion: This is exactly the type of progress that transforms quantum computing from laboratory theory into engineering reality. The transition from two nodes to three radically complicates the task, but it is precisely such steps that bring us closer to the moment when quantum networks become as commonplace as classical ones.