Breakthrough in Quantum Networks: Scientists Entangle Three Remote Atomic Qubits for the First Time
Quantum entanglement is one of the most mysterious and promising phenomena in modern physics. It allows particles to remain inextricably linked at any distance, instantly responding to changes in each other. This effect is the foundation of future quantum networks and the so-called "quantum internet." Recently, researchers from Duke University and the company IonQ achieved a real breakthrough by creating the first fully distributed three-node quantum network based on individual atomic qubits.
The Essence of the Experiment
The specialists managed to form a three-party entangled state (Greenberger–Horne–Zeilinger state) between three remote quantum nodes. These nodes were connected via photonic channels, enabling the creation of a unified quantum system. Previously, similar results were achieved on other physical platforms, but this is the first time it has been done with individual atomic qubits. The key advantage of this approach is the ability to independently control, read, and scale these qubits for building computational systems.
Why This Matters
The main challenge of modern quantum computers is scaling. Building a single large quantum processor is incredibly difficult due to errors and hardware limitations. That is why many developers are betting on a modular architecture: instead of one giant computer, a network of multiple quantum nodes connected by photons is constructed. This approach resembles the development of the classical internet, where computing resources are distributed across many servers.
The new experiment is an important step in this direction. The researchers showed that individual atomic memories can form a shared quantum state through photonic connections while maintaining high operational accuracy. During the experiment, the fidelity of the entangled state reached 84–88%. Moreover, for the first time, they 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 demonstrating the presence of genuine quantum correlations.
A Step Toward the Quantum Internet
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 expanded the architecture to three full-fledged nodes. Although the technology is still far from commercial application, such experiments are considered important building blocks for future distributed quantum computers, secure communication networks, and ultimately, the quantum internet.
Expert Opinion: This breakthrough is not just an academic victory. It proves that the modular architecture of quantum systems is viable and scalable. For the crypto industry, this is especially important: distributed quantum networks could become the foundation for ultra-secure communications and new encryption methods, which giants like Colt and Ciena are already beginning to test. We stand on the threshold of an era where quantum mechanics ceases to be a theory and becomes a practical tool.