Breakthrough in Quantum Networks: Scientists Entangle Three Remote Atomic Qubits for the First Time
Quantum entanglement is a phenomenon where the state of one particle instantly influences another, regardless of the distance between them. This effect underpins future quantum networks and the quantum internet. However, until recently, scientists could only demonstrate entanglement between two remote nodes. Now, researchers from Duke University and IonQ have achieved a breakthrough by creating the first fully distributed three-node quantum network based on individual atomic qubits.
In the experiment, specialists managed to form a three-party entangled state known as the Greenberger-Horne-Zeilinger (GHZ) state. Three quantum nodes, each representing a single atomic qubit, were linked via photonic channels. This is the first time such a result has been achieved for individual atomic qubits that can be independently controlled, read out, and scaled to build computational systems.
Why This Is a Breakthrough
The main challenge for quantum computers is scaling. Creating a single large quantum processor is extremely difficult due to errors and hardware limitations. Therefore, many developers are betting on a modular architecture: instead of one giant computer, a network of many quantum nodes connected by photons is built. This approach mirrors the development of the classical internet, where computing resources are distributed across multiple servers.
The new experiment is a step in this direction. Researchers demonstrated that individual atomic memories can form a shared quantum state through photonic connections while maintaining high fidelity in quantum operations. In the experiment, the fidelity of the entangled state reached 84–88%. Additionally, for the first time, the so-called "detection loophole" was closed for a fully distributed multi-component quantum state. The results also confirmed the violation of Mermin's 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 IonQ studies on photonic quantum connections. Previously, the company's specialists demonstrated entanglement between two remote ion systems, and now they have expanded the architecture to three full 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 the quantum internet.
Analyst's opinion: This breakthrough is not just a scientific sensation but a practical step toward creating the quantum internet. The modular architecture, where each node is a separate atomic qubit, solves the scaling problem that has long hindered the development of quantum computing. If the pace of research continues, we could see the first commercial prototypes of distributed quantum networks within the next 5-7 years.