Brookhaven Lab and Stony Brook send quantum data through the air

Researchers at Brookhaven National Laboratory and Stony Brook University have achieved the first U.S. demonstration of quantum data transmitted through open air, extending the reach of the nation’s longest quantum network beyond fiber-optic cable limitations. During a demonstration on Friday, Aug. 21, scientists successfully sent light particles carrying quantum information 13 miles between the Stony Brook University’s Quantum Watchtower and Brookhaven’s Quantum Lighthouse, a rooftop facility built for this purpose. “The future of quantum information science will depend not only on what individual quantum computers and devices can do but on our ability to connect them,” said DOE Under Secretary for Science Darío Gil. This free-space optical link adds a wireless component to the network already connecting eight nodes. Free-Space Optical Link Bridges Brookhaven and Stony Brook Brookhaven National Laboratory’s Quantum Lighthouse, a dedicated rooftop facility, served as the receiving point for the first U.S. demonstration. Realized in collaboration with Stony Brook University, this achievement bypasses the limitations inherent in fiber-optic cable networks by utilizing a free-space optical link stretching 13 miles between the two institutions. 21, showcasing the precision required to maintain quantum states across such a distance. The newly established wireless component relies on an intricate system of optics and controls, integrating quantum sources and detectors across the 21-kilometer span. Justine Haupt, Brookhaven Lab’s lead scientist on the project, explained the challenges, stating, “We needed to integrate the optics, controls, communications, quantum sources, and detectors so equipment 21 kilometers apart could operate as one experiment.” This integration was crucial for maintaining the delicate quantum states of the photons as they traversed the open air, a feat complicated by atmospheric turbulence.

The team drew upon expertise typically used in astronomy to develop adaptive optics technology capable of correcting for these distortions, ensuring signal fidelity. This demonstration extends a network already connecting eight nodes across several institutions. Eden Figueroa, director of Stony Brook’s Quantum Institute, highlighted the potential for future advancements, noting, “In our long-distance fiber network, we routinely transmit entangled pairs of photons. However, such fiber networks are limited to the use of telecom wavelengths.” In their new quantum wireless links, researchers are exploring the use of infrared wavelengths that are native to quantum processors and related technologies. This shift to infrared wavelengths promises a more direct connection between quantum systems, enabling the creation of entangled atomic systems over greater distances. “We will continue advancing the network’s capabilities so that researchers can connect increasingly sophisticated quantum systems together to address a range of problems, from computation to communication to sensing, in ways that just aren’t possible today.” The partnership between Stony Brook and Brookhaven, according to Stony Brook University President Andrea Goldsmith, demonstrates how collaboration can advance discovery and create transformative technologies. Both Brookhaven and Stony Brook needed to build specialized rooftop facilities for the telescope systems that were optimized for quantum experiments. Justine Haupt, Brookhaven Lab’s lead scientist on the cross-institutional FSO link project Quantum Watchtower and Lighthouse Enable Photon Transmission This first-of-its-kind U.S. achievement utilized a newly established free-space optical (FSO) link, extending the quantum network already connecting eight nodes and paving the way for a more versatile quantum internet. Researchers transmitted photons carrying quantum information across 13 miles of open air, a feat previously limited by the constraints of traditional fiber infrastructure. Central to this advancement are Brookhaven’s Quantum Lighthouse and Stony Brook’s Quantum Watchtower, specialized rooftop facilities designed to optimize quantum experiments. The transmission began at the Quantum Watchtower, where a laser generated quantum states of light exiting a fiber about 5 microns in diameter. This beam traveled to the Quantum Lighthouse, a building specifically chosen for its clear line of sight to Stony Brook, allowing researchers to receive and measure the photons with an ultrafast camera.

The team leveraged astronomical adaptive optics technology to counteract atmospheric turbulence, ensuring the fragile quantum information remained intact during transmission. Beyond simply sending photons, the team successfully transmitted entangled photons, pairs of light particles linked by quantum mechanics, via the FSO link. During nighttime tests, entangled photons were sent from a Stony Brook physics laboratory through fiber to the Quantum Watchtower, then distributed wirelessly to the Quantum Lighthouse. The development of this wireless capability unlocks new possibilities for quantum communication, sensing, and computing. Unlike traditional fiber networks limited to telecom wavelengths, this new link explores infrared wavelengths native to quantum processors. The success of this project is not merely a technical achievement; it represents a significant stride toward realizing a fully interconnected quantum ecosystem. “As DOE advances its Genesis Mission, we are building toward an interconnected research ecosystem where advanced computing, artificial intelligence, and quantum technologies can work together to tackle some of our most complex scientific challenges.” Brookhaven has long been at the forefront of quantum information science, and this achievement represents another important step in that journey. John Hill, Brookhaven Lab Director The experiment utilized a free-space optical (FSO) link, transmitting photons across 13 miles of open air. This precision was critical, as the receiving aperture at Brookhaven’s Quantum Lighthouse required equally precise alignment to detect the arriving photons. The connection between Stony Brook and Yale is currently under development. Long Island has long been home to some of the world’s most important scientific institutions, and today’s milestone demonstrates what is possible when those institutions work together. Kevin Law, Empire State Development Board Chairman Mile FSO Link Extends Long Island Quantum Network This first U.S. This wireless capability was not simply about sending photons, but about maintaining the delicate quantum properties of entangled photons across a considerable distance. The precision required for this experiment was considerable, mirroring challenges faced by astronomers. Scientists leveraged technologies developed for collecting and controlling light from distant stars to compensate for atmospheric turbulence, ensuring the fragile quantum signals remained coherent over the 21-kilometer distance. During a daytime demonstration on Friday, Aug. 21, researchers used a laser to generate quantum states of light, each containing just a few individual photons. Brookhaven has long been involved in quantum information science, and this achievement represents another important step in that journey,” said Gabriella Carini, Associate Laboratory Director for Discovery Technologies at Brookhaven.

New York State’s commitment to investing in emerging fields is also evident, with officials highlighting the potential for Long Island to become an innovation hub for quantum technologies. “By unlocking wireless quantum connectivity and incorporating it into the world’s only metropolitan-area network that supports quantum communication via entanglement, we are transforming secure data transmission,” stated Stony Brook University President Andrea Goldsmith. The success of this project demonstrates the power of collaboration and lays the groundwork for a future where quantum networks connect researchers and institutions across vast distances. By unlocking wireless quantum connectivity and incorporating it into the world’s only metropolitan-area network that supports quantum communication via entanglement, we are transforming secure data transmission while igniting Long Island as an innovation hub. Andrea Goldsmith, State University of New York at Stony Brook President Infrared Wavelengths Advance Quantum Processor Connectivity This connection, the first of its kind demonstrated in the United States, utilizes infrared wavelengths to transmit quantum information, a departure from the telecom wavelengths typically used in fiber networks. Brookhaven’s contribution to this advancement is particularly visible in the Quantum Lighthouse, a dedicated rooftop facility equipped with specialized optics and control systems. The future of quantum information science will depend not only on what individual quantum computers and devices can do but on our ability to connect them. Darío Gil, DOE Under Secretary for Science Source: https://www.bnl.gov/newsroom/news.php?a=123096 Stay currentSee today’s quantum computing news on Quantum Zeitgeist for the latest breakthroughs in qubits, hardware, algorithms, and industry deals. Tags: