Quantum milestone achieved: scientists have for the first time entangled three remote atomic qubits into a single network
The world of quantum computing has received yet another proof that distributed architectures are not a futuristic fantasy, but a very real engineering challenge. A team of researchers from Duke University and IonQ has announced the creation of the first fully distributed three-node quantum network, built on the basis of individual atomic qubits. This is not just a laboratory curiosity, but a serious step toward modular quantum computers and, in the long term, toward a quantum internet.
The key achievement is the formation of the so-called Greenberger-Horne-Zeilinger state (GHZ state) between three remote quantum nodes connected by photonic channels. The GHZ state is a classic example of multi-component quantum entanglement, where a change in the state of one qubit is instantly reflected in all others, regardless of distance.
Why is this a breakthrough?
Previously, entanglement between two remote qubits has been demonstrated multiple times. Moreover, three-node networks have already been created on other physical platforms, such as those based on photons or superconductors. However, for the first time, a similar result has been achieved for individual atomic qubits, which can be independently controlled, read out, and, most importantly, scaled. Atomic systems are considered among the most promising for building computational cores due to their stability and low noise levels.
The main headache of the quantum industry is scaling. Building a single giant quantum processor with thousands of error-free qubits is a task bordering on impossibility. Therefore, the modularity strategy, where instead of a monolithic chip, a network of many quantum nodes connected by photons is created, looks the most pragmatic. This experiment is a direct demonstration that such an architecture works.
Numbers and tests
During the experiment, the scientists achieved a fidelity of the entangled state at the level of 84–88%. Moreover, for the first time, they managed to close the so-called "detection loophole" for a fully distributed multi-component quantum state. Additionally, the results confirmed the violation of the Mermin inequality — one of the strictest tests that unequivocally proves the presence of genuine quantum correlations, rather than classical statistics.
This is an important step for IonQ, which is consistently developing the technology of photonic quantum interconnects. Previously, the company demonstrated entanglement between two remote ion systems, and now it has expanded the architecture to three full-fledged nodes. Although commercial application is still far off, such experiments lay the foundation for distributed quantum computers, secure communications, and, ultimately, the quantum internet.
My conclusion: The demonstration of a three-node network on atomic qubits is not just another record, but a practical proof that the modular approach to quantum computing is viable. If engineers can scale this architecture to dozens and hundreds of nodes, we will witness a true quantum revolution, comparable to the transition from mainframes to distributed cloud computing.