Breakthrough in Quantum Networks: Scientists Entangle Three Distant Atomic Qubits for the First Time
Quantum computing takes another significant step forward. A research team from Duke University and IonQ has announced the creation of the first fully distributed three-node quantum network based on individual atomic qubits. This event marks a crucial milestone on the path to a practical quantum internet and modular quantum computers.
The key achievement was the formation of a so-called three-party entangled state (GHZ state) between three remote quantum nodes connected by photonic channels. Quantum entanglement is a phenomenon where a change in the state of one particle instantly affects another, regardless of distance. Previously, such effects were demonstrated on two nodes or on other physical platforms, but now, for the first time, this has been realized on atomic qubits that can be independently controlled and scaled.
Why This Changes the Game
The main headache for quantum computer developers is scaling. Creating a single massive quantum processor without critical errors and hardware limitations is practically impossible. That is why more and more experts are betting on a modular architecture: instead of a monolithic chip, a network of many quantum nodes connected by photons is built. This resembles the evolution of the classical internet, where computing power is distributed across thousands of servers.
The new experiment is direct confirmation of the viability of this approach. Scientists showed that individual atomic memories can form a common quantum state through photonic connections while maintaining high operational accuracy. During tests, the fidelity of the entangled state reached 84–88%. Moreover, for the first time, it was possible to close the "detection loophole" for a fully distributed multi-component quantum state, as well as confirm the violation of the Mermin inequality—one of the main tests for genuine quantum correlations.
The Path to a Quantum Internet
This work continues a series of IonQ studies in the field of photonic quantum connections. Previously, the company demonstrated entanglement between two remote ion systems, and now it has expanded the architecture to three full-fledged nodes. Although commercial application is still far off, such experiments are fundamental building blocks for future distributed quantum computers, secure communication networks, and, ultimately, the quantum internet.
My expert opinion: Achieving 84-88% fidelity in a three-node network is a significant result that exceeds expectations. Closing the "detection loophole" is especially important, as it eliminates one of the key doubts about the authenticity of quantum effects. We are witnessing the quantum network transition from theoretical models to engineering reality, and this promises a revolution in secure communications and distributed computing.