Breakthrough in quantum networks: scientists have entangled three remote atomic qubits for the first time
The world of quantum computing is taking another significant step forward. Researchers from Duke University and IonQ have announced the creation of the first fully distributed three-node quantum network based on individual atomic qubits. This achievement opens new horizons for modular quantum architectures and brings us closer to the era of the quantum internet.
The Essence of the Experiment
Quantum entanglement is a fundamental phenomenon in which multiple particles remain inextricably linked, regardless of the distance between them. A change in the state of one particle is instantly reflected in the others. In the new experiment, specialists managed to form a three-party entangled state (GHZ state) between three remote quantum nodes connected by photonic channels. Previously, similar results were achieved on other physical platforms, but this is the first time it has been realized for individual atomic qubits that can be independently controlled and scaled.
Why This Is a Breakthrough
The main problem with modern quantum computers is scaling. Building one giant quantum processor is extremely difficult due to hardware limitations and errors. An alternative approach is a modular architecture, where instead of one huge computer, a network of many quantum nodes connected by photons is created. This resembles the development of the classical internet, where resources are distributed across servers.
The new experiment demonstrates that individual atomic memories can form a shared quantum state through photonic connections while maintaining high operational accuracy. The fidelity of the entangled state was 84–88%. Additionally, for the first time, scientists closed the so-called "detection loophole" for a fully distributed multi-component quantum state and confirmed the violation of the Mermin inequality—a key test for genuine quantum correlations.
The Path to the Quantum Internet
This research continues a series of IonQ's works in the field of photonic quantum connections. Previously, the company demonstrated entanglement between two remote ion systems, and now it has successfully expanded the architecture to three nodes. Although the technology is still far from commercial application, such experiments are considered critically important building blocks for future distributed quantum computers, secure communication networks, and the quantum internet.
Expert Opinion: This result is not just a laboratory curiosity but a crucial step toward the practical implementation of quantum networks. The successful creation of a three-node system with high accuracy and the closure of the "detection loophole" proves that a modular architecture based on atomic qubits is viable. In the coming years, we will likely see scaling to 5-10 nodes, which will form the basis for the first prototypes of the quantum internet.