Chinese Researchers Report Quantum Entanglement Over 30 Miles of Fiber Potentially Bringing Quantum Internet Closer

(TechnologyReview) Pan Jian-Wei at the University of Science and Technology of China, in Hefei, and his colleagues have described an experiment in which they demonstrate entanglement through more than 30 miles of fiber coiled in a lab, with lower transmission errors than previous attempts. “This is a big improvement,” says Pan, who is sometimes called the “father of quantum.” The trick was to find efficient ways to entangle two particles.
“It’s nice, but not nearly as big as it sounds,” says Stephanie Wehner, a researcher at QuTech, a quantum computing and quantum internet research centre in Delft in the Netherlands. Pan’s team used 30 miles of coiled fiber, which still demands an impressive degree of control over the whole system, but demonstrating entanglement between two nodes in one location is much easier than when they are actually 30 miles apart.
Pan’s team also claims that its set-up is more reliable than previous examples and thus lays better groundwork for an actual quantum internet. The methods developed in this work could be used to build quantum networks between cities in the near future, he says.