Exclusive: The world's first three-node quantum network based on individual atoms — a breakthrough toward modular quantum computers
A team of researchers from Duke University and IonQ has achieved a significant breakthrough in quantum technology, creating the first fully distributed three-node quantum network based on individual atomic qubits. This achievement marks an important step toward practical modular quantum computing systems and the quantum internet.
The Essence of the Experiment: GHZ State at a Distance
For the first time, specialists have managed to form a so-called three-party entangled state (Greenberger–Horne–Zeilinger state, or GHZ state) between three remote quantum nodes. These nodes were connected via photonic channels, allowing the creation of a unified quantum system where a change in the state of one qubit is instantly reflected in all others, regardless of distance.
Previously, similar experiments were conducted on other physical platforms, but for atomic qubits—which can be independently controlled, read out, and scaled—this result has been achieved for the first time. Atomic qubits are considered among the most promising for building full-fledged computing machines due to their stability and controllability.
Why This Changes the Game
The main problem with modern quantum computers is scaling. Building one giant quantum processor is incredibly difficult due to error accumulation and physical limitations. This is why the industry is increasingly moving toward a modular architecture, reminiscent of the development of the classical internet: instead of one supercomputer, a network of many quantum nodes connected by photons is created.
The new experiment clearly demonstrates that individual atomic memories can form a common quantum state through photonic connections while maintaining high operational accuracy. The fidelity of the resulting entangled state was 84–88%, which is an excellent indicator for such complex systems.
Furthermore, scientists have for the first time managed to close the so-called "detection loophole" for a fully distributed multi-component quantum state. The results also confirmed the violation of the Mermin inequality—one of the key tests proving the presence of genuine quantum correlations rather than classical imitations.
A Look to the Future
Although the technology is still far from commercial application, this experiment is an important building block for future distributed quantum computers, secure communication networks, and the quantum internet. The work continues a series of IonQ studies on photonic quantum connections: the company previously demonstrated entanglement between two nodes and has now successfully expanded the architecture to three full nodes.
My expert opinion: This result confirms that the modular approach to quantum computing is not just a theoretical concept but a truly working technology. Achieving a three-node network on atomic qubits with the closure of the "detection loophole" is not just a record but a demonstration that we can build quantum systems that truly scale. The next logical step is to increase the number of nodes to tens and hundreds, which could happen faster than many expect.