Quantum teleportation at a new level: three remote atomic qubits entangled for the first time
A team of researchers from Duke University and IonQ has achieved a breakthrough in quantum communications. They have successfully created the first fully distributed three-node quantum network based on individual atomic qubits. The key achievement was the formation of the so-called Greenberger-Horne-Zeilinger (GHZ) state — a three-party quantum entanglement between three remote nodes connected via photonic channels.
What is quantum entanglement and why is it difficult?
Quantum entanglement is a fundamental phenomenon where two or more particles remain interconnected, regardless of the distance between them. A change in the state of one particle instantly affects the state of another. This effect is a cornerstone for future quantum networks and the quantum internet. Previously, scientists demonstrated entanglement between two nodes and also created three-node networks on other platforms. However, this is the first time such a result has been achieved for individual atomic qubits that can be independently controlled, read out, and, most importantly, scaled to build computational systems.
Why is this important for the future of quantum computing?
The main problem with modern quantum computers is scaling. Building a single giant quantum processor is incredibly difficult due to high error rates and physical limitations. This is why many leading developers are betting on a modular architecture. Instead of one monolithic computer, a network of many quantum nodes connected by photons is created. This approach mirrors the evolution of the classical internet, where computing 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 shared quantum state through photonic connections while maintaining high fidelity of quantum operations. During the experiment, the fidelity of the entangled state reached 84–88%. Moreover, scientists closed the so-called "detection loophole" for a fully distributed multi-component quantum state for the first time. The results also confirmed the violation of the Mermin inequality — one of the key tests that unequivocally proves the presence of genuine quantum correlations rather than classical statistical coincidences.
A step towards the quantum internet
This work continues a series of IonQ studies on photonic quantum connections. Previously, they demonstrated entanglement between two remote ion systems, and now they have successfully expanded the architecture to three full nodes. Although the technology is still far from commercial application, such experiments are critically important building blocks for future distributed quantum computers, secure communication networks, and, ultimately, the quantum internet.
My comment: This experiment solves one of the main engineering challenges on the path to a scalable quantum computer. Demonstrating three-party entanglement on individual atoms is not just a record, but proof that the modular approach is viable. If we can connect qubits through photonic channels with such precision, creating a distributed quantum computer from thousands of nodes ceases to be science fiction and becomes a matter of engineering optimization.