Quantum network on atoms: experts have entangled three remote qubits for the first time
A team of researchers from Duke University and IonQ has achieved a breakthrough in the field of distributed quantum computing. For the first time in history, they have created a three-way entangled state (GHZ state) between three separate atomic qubits, spaced apart in space and connected by photonic channels. This is the first time such a result has been achieved specifically on a platform of individual atoms that can be individually controlled and scaled.
Technical Essence of the Experiment
Quantum entanglement is a phenomenon where particles remain inextricably linked, regardless of the distance between them. A change in one instantly affects the other. Previously, scientists have demonstrated entanglement between two nodes and have also created three-node networks on other physical platforms. However, the current experiment is unique because it is the first to be implemented on individual atomic qubits—key elements for building full-fledged quantum processors.
During the work, the researchers achieved a fidelity of the entangled state at the level of 84–88%. Moreover, for the first time, they managed to close the "detection loophole" for a fully distributed multi-component quantum state. Additional confirmation came from the observation of a violation of the Mermin inequality—one of the strict tests proving the presence of genuine quantum correlations.
Why This Matters for the Industry
The main problem with modern quantum computers is scaling. Creating a single giant processor with millions of qubits is incredibly difficult due to errors and physical limitations. This is why more and more developers are moving to a modular architecture: instead of a monolithic device, a network of many quantum nodes connected by photons is built. This resembles the evolution of the classical internet, where resources are distributed across thousands of servers.
The new experiment is a direct step in this direction. It proves that individual atomic memories can form a common quantum state through photonic connections while maintaining high operational accuracy. Previously, IonQ had already demonstrated entanglement between two remote ion systems, and now the architecture has been expanded to three full-fledged nodes.
Although the technology is still far from commercial application, such results are the foundation for future distributed quantum computers, secure communication networks, and ultimately, the quantum internet.
My comment: This experiment marks a transition from theory to practice in the field of quantum networks. Achieving three-way entanglement on atomic qubits with the closure of detection loopholes is not just a laboratory record, but a real step towards creating fault-tolerant distributed quantum systems. Investors and developers should keep a close eye on IonQ: the modular approach is becoming mainstream.