Real-world experiment in Chicago suburbs achieves quantum entanglement across 52-mile fiber network

Scientists from Argonne National Laboratory and the University of Chicago entangled photons across a 52-mile network in the Chicago suburbs, an important step in developing a national quantum internet.

The quantum loop, spearheaded by UChicago professor and Argonne senior scientist David Awschalom, ran its first successful entanglement experiments on Feb. 11. Headquartered at Argonne, the loop is among the longest land-based quantum networks in the nation. 

The experiment, funded by the U.S. Department of Energy’s Office of Science Basic Energy Sciences, is seen as a foundational building block in the development of a quantum internet— potentially a highly secure and far-reaching network of quantum computers and other quantum devices. A quantum internet could catalyze technologies that greatly accelerate today’s internet, significantly improve the security of communications, and support dramatic advances in computing and sensing. Scientists say quantum technology could revolutionize national and financial security, patient privacy, drug discovery, and the design and manufacturing of new materials, while increasing our scientific understanding of the universe.

“This is an important step forward in harnessing entanglement and building a network to help form the basis of future quantum communication systems,” said Awschalom, the Liew Family Professor in the Pritzker School of Molecular Engineering at UChicago, senior scientist in the Materials Science Division at Argonne and director of the Chicago Quantum Exchange. “We are excited by these initial demonstrations of distributing entanglement outside of a laboratory, as well as having a flexible communications platform that allows us to identify the challenges of translating quantum phenomena to the real world.”

In the subatomic quantum world, particles can become entangled, sharing their states even though they’re in different locations—a phenomenon which could be used to transfer information. The network, which originates at Argonne in Lemont, Ill. and winds circuitously in a pair of 26-mile loops through several of Chicago’s western suburbs, taps the unique properties of quantum mechanics to eventually “teleport” information virtually instantaneously across a distance. As a bonus, scientists believe the information would be extremely difficult to hack: Quantum states change when observed, so the presence of an outside listener would actually change the signal itself.

Read more at UChicago News.