Breakthrough in Quantum Networks: Scientists Entangle Three Remote Atomic Qubits for the First Time
The world of quantum computing takes another significant step forward. A research team from Duke University, in collaboration with IonQ, has announced the creation of the first fully distributed three-node quantum network based on individual atomic qubits. This achievement marks a crucial milestone on the path to building a scalable quantum internet.
The key result of the work was the demonstration of a so-called three-party entangled state (Greenberger–Horne–Zeilinger, or GHZ state) between three remote quantum nodes. These nodes were interconnected via photonic channels, enabling the creation of a unified quantum system where a change in the state of one qubit instantly affects the state of the other two, regardless of distance.
What does this mean for the industry?
Until now, scientists have successfully demonstrated entanglement between two remote nodes and have also built three-node networks on other physical platforms. However, this is the first time such a result has been achieved specifically with individual atomic qubits. This is fundamentally important because such qubits possess unique properties: they can be independently controlled, read out, and, most importantly, scaled to build full-fledged computing systems.
The main challenge for modern quantum computers is scaling. Creating a single giant quantum processor involves enormous technical difficulties due to errors and hardware limitations. This is why more and more developers are betting on a modular architecture. Instead of one monolithic computer, the idea is to create a network of many quantum nodes connected by photons. This approach resembles 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. The researchers showed 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 an impressive 84–88%. Moreover, the scientists managed to close 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 proving the existence of genuine quantum correlations.
A look into the future
This work continues a series of studies by the IonQ team in the field of photonic quantum connections. Previously, the company's specialists had already demonstrated entanglement between two remote ion systems, and now they have successfully expanded the architecture to three full-fledged 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.
Expert opinion: This achievement is not just a laboratory curiosity. It proves that the modular approach to building quantum systems is viable. Real commercialization will likely take another 5-10 years, but it is precisely such steps that turn quantum computing from science fiction into engineering reality. Investors should pay attention to companies actively working in this field — they are shaping the infrastructure of tomorrow.