Breakthrough in quantum networks: scientists have entangled three remote atomic qubits for the first time
The quantum industry has taken an important step toward creating distributed computing systems. A research team from Duke University, in collaboration with IonQ, announced the achievement of three-party quantum entanglement between individual atomic qubits located in remote nodes. This is the world's first fully distributed three-node quantum network on this physical platform.
The experiment is based on the formation of a Greenberger-Horne-Zeilinger (GHZ) state — one of the fundamental types of multipartite quantum entanglement. Three nodes were connected via photonic channels, allowing their quantum states to be synchronized.
Why is this a breakthrough?
Until now, entanglement could only be demonstrated between two remote quantum nodes. Three-node networks existed on other physical platforms, but for individual atomic qubits, which can be independently controlled and read out, this result has been achieved for the first time. This is critically important for scaling: the modular architecture of quantum computers, where each node is a separate processor connected by photons, is considered the most promising approach to overcoming current limitations in size and errors.
The key metrics of the experiment are impressive: the fidelity of the entangled state reached 84–88%. Moreover, scientists managed to close the "detection loophole" for a fully distributed multipartite quantum state for the first time. This means the results cannot be explained by classical effects or measurement errors. Additionally, the violation of the Mermin inequality — a rigorous test proving the presence of genuine quantum correlations — was confirmed.
A step toward the quantum internet
This work continues a series of IonQ studies in the field of photonic connections. Previously, the company demonstrated entanglement between two ion systems, and now it has expanded the architecture to three nodes. Although commercial application is still far off, such experiments are building blocks for future distributed quantum computers, secure communication networks, and ultimately, the quantum internet.
My analysis: This result is not just a laboratory curiosity. It demonstrates that the modular approach to quantum computing is viable. The successful closure of the "detection loophole" and high fidelity indicate that we are moving from theoretical models to practical prototypes. For the crypto industry, this is a signal: quantum-resistant solutions, such as those tested by Colt and Ciena, are becoming not a luxury but a necessity, and the time for preparation is shrinking.