Breakthrough in Quantum Networks: Scientists Entangle Three Remote Atomic Qubits for the First Time
Quantum entanglement is a phenomenon in which two or more particles remain inextricably linked, regardless of the distance between them. A change in the state of one particle instantly affects all others, making this effect key to creating the future quantum internet. Researchers from Duke University and IonQ have achieved a significant breakthrough by demonstrating, for the first time, three-way entanglement between three remote atomic qubits connected via photonic channels.
As part of the experiment, a so-called GHZ configuration (Greenberger–Horne–Zeilinger) was formed, which is a classic example of multi-component quantum correlation. Previously, such networks were created on other physical platforms, but for individual atomic qubits that can be independently controlled and scaled, this achievement is the first of its kind.
Why This Matters for the Industry
The main challenge for modern quantum computers is scaling. Building a single giant processor with millions of qubits is extremely difficult due to high error rates and physical limitations. An alternative approach, actively pursued by market leaders, is a modular architecture. Instead of one monolithic device, a network of many quantum nodes connected by photons is created. This resembles the evolution of the classical internet, where computing resources are distributed across servers.
The new experiment demonstrates that individual atomic memories can form a shared quantum state through photonic connections with high precision. The fidelity of the entangled state was 84–88%, which is an excellent indicator for this type of operation. Moreover, for the first time, scientists managed to close the "detection loophole" for a fully distributed multi-component state and confirm the violation of the Mermin inequality — a rigorous test for the presence of genuine quantum correlations.
A Step Toward Commercialization
The work continues a series of IonQ studies on photonic connections. Previously, the company demonstrated entanglement between two remote ion systems, and now the architecture has been expanded to three full nodes. Although commercial application is still far off, such experiments are the foundation for future distributed quantum computers, secure communication networks, and ultimately, the quantum internet.
Expert opinion: The achievement of three-way entanglement on individual atomic qubits is not just a laboratory curiosity but a crucial step toward the practical implementation of modular quantum systems. Fidelity rates of 84–88% indicate the maturity of the technology, and I expect that within the next 2-3 years, we will see the first prototypes of distributed quantum computing networks capable of solving real-world problems such as cryptography and optimization of complex systems.