Researchers Takes Major Step Toward a Wireless Quantum Internet; Send Quantum Information 13 Miles Through Open Air

BROOKHAVEN, NY – Researchers at Stony Brook University and Brookhaven National Laboratory have successfully transmitted quantum information through 13 miles of open air, marking what the institutions described as the first demonstration of its kind in the United States.

The experiment connected Stony Brook’s Quantum Watchtower, located atop its Health Sciences Center, with Brookhaven’s Quantum Lighthouse in Upton. According to the joint announcement published by Stony Brook University, the achievement represents an important step toward extending quantum networks beyond the physical limitations of fiber-optic cables.

During a daytime demonstration on August 21, researchers used a laser to produce quantum states of light containing only a few photons. The particles left an optical fiber with a core less than one-tenth the width of a human hair and traveled approximately 13 miles before reaching Brookhaven’s detector.

The more consequential tests occurred at night, when lower levels of background light made it easier to detect the fragile signal. Researchers successfully sent entangled photons from a Stony Brook laboratory to the rooftop Watchtower and then through open air to Brookhaven, where they were received and measured.

Entangled photons are pairs of light particles whose properties remain connected even when they are separated. That relationship could eventually support highly secure communications, advanced sensing and networks of quantum computers capable of working together.

The significance is that future quantum computers may need to be connected in much the same way conventional computers are connected through the internet. Fiber-optic cables can carry quantum information, but they cannot reach every location and are difficult to extend across water, remote areas or into space. Successfully sending quantum information through open air gives researchers another way to connect those systems, potentially creating communications that are far more difficult to intercept and allowing powerful quantum computers in different locations to operate together.

The new wireless link supplements an existing quantum network spanning 161 miles and eight nodes across Long Island and the New York City metropolitan area. A third facility has also been completed at Yale University, where researchers plan to establish a roughly 30-mile connection across Long Island Sound.

The longer-term goal is even more ambitious. Researchers envision connecting quantum systems through satellites, potentially turning what began as a regional network on Long Island into part of a global quantum communications system.

“We needed to integrate the optics, controls, communications, quantum sources, and detectors so equipment 21 kilometers apart could operate as one experiment,” Brookhaven scientist Justine Haupt said in the announcement.

Key Facts and Details

The project is supported primarily by the U.S. Department of Energy’s Office of Science, the National Science Foundation and New York’s Empire State Development. Gov. Kathy Hochul’s office also highlighted the experiment as a milestone in New York’s effort to become a leader in quantum research and secure communications.