Breakthrough in quantum networks: three-way entanglement of remote atomic qubits achieved for the first time
The quantum industry is taking another step toward creating distributed computing systems. In a recent experiment, researchers successfully achieved three-way quantum entanglement — a Greenberger–Horne–Zeilinger (GHZ) state — between three remote nodes based on individual atomic qubits. This is the first demonstration of its kind for such an architecture, where nodes are connected via photonic communication channels.
Essence of the Experiment
Quantum entanglement remains one of the most intriguing phenomena in physics: a change in the state of one particle instantly affects the state of another, regardless of distance. Previously, researchers have achieved entanglement between two remote nodes and built three-node networks on other physical platforms. However, the key difference in this new achievement is the use of individual atomic qubits, which can be independently controlled, read out, and — critically — scaled to build full-fledged computing systems.
Why This Is a Breakthrough
The main challenge for modern quantum computers is scaling. Creating a single giant processor involves enormous technical difficulties and high error rates. That is why many developers are betting on a modular architecture: instead of one monolithic device, a network of many quantum nodes connected by photons is built. This resembles the evolution of the classical internet, where computing resources are distributed across servers.
In the experiment, researchers demonstrated 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%. Moreover, for the first time, they managed to close the so-called "detection loophole" for a fully distributed multi-component quantum state. The results also confirmed the violation of the Mermin inequality — one of the key tests proving the presence of genuine quantum correlations.
Path to the Quantum Internet
This experiment is an important building block for future distributed quantum computers, secure communication networks, and ultimately, the quantum internet. Although the technology is still far from commercial application, such results confirm the fundamental feasibility of creating scalable quantum networks based on atomic systems.
Analyst's Comment: The quantum technology market is at a stage where every such experiment brings us closer to practical implementation. Achieving three-way entanglement with high fidelity is not just a scientific demonstration but a clear signal to investors and developers: modular architecture is becoming a real alternative to traditional approaches. Over the next 3–5 years, we will likely see the first prototypes of distributed quantum computers capable of solving problems inaccessible to classical systems.