Argonne, UChicago scientists perform initial measurements on 52-mile fiber-optic testbed

Scientists from Argonne National Laboratory and the University of Chicago launched a new testbed for quantum communication experiments from Argonne last week.

The quantum loop consists of a pair of connected 26-mile fiber-optic cables that wind circuitously between Argonne to the Illinois Tollway near suburban Bolingbrook and back. At 52 total miles, it is among the longest ground-based quantum communication channels in the country.

The loop will serve as a testbed for researchers interested in leveraging the principles of quantum physics to send unhackable information across long distances. Researchers at Argonne and UChicago plan to use the testbed to explore science underlying quantum engineering systems and to harness the properties of quantum entanglement—a phenomenon Albert Einstein famously characterized as “spooky action at a distance.” Quantum entanglement links two (or more) particles so that they are in a shared state—such that whatever happens to one immediately affects the other, no matter how far they have traveled apart.

“Inaugurating this quantum loop is a significant step for Chicago and the nation in building a large-scale quantum network that can enable secure data transmissions over long distances,” said principal investigator David Awschalom, senior scientist in the Materials Science Division at Argonne, the Liew Family Professor in Molecular Engineering at the University of Chicago and director of the Chicago Quantum Exchange. “The loop will enable us to identify and address challenges in operating a quantum network and can be scaled to test and demonstrate communication across even greater distances to help lay the foundation for a quantum internet.”

Argonne scientists Joe Heremans, Alan Dibos and Gary Wolfowicz, who worked on the quantum loop project, demonstrated the operation of the testbed by generating and transmitting optical pulses through one and then both fiber loops. They witnessed a delay of 200 microseconds for the transit time of the laser pulse along one fiber loop, which is consistent with the speed of light in the glass fiber.

Read more at UChicago News.

Photo: Argonne scientist Alan Dibos works on optic equipment for the 52-mile quantum testbed. Courtesy of Argonne National Laboratory.