The team used real-time polarization stabilization technology developed by Qunnect to maintain photon entanglement despite environmental disturbances affecting the fiber. <\/p>\n
The experiment distributed entangled photons at a rate of 1,500 per second and maintained entanglement for 92.8% of a 24-hour test period.<\/p>\n
This article is based on reporting and material published by the National Institute of Standards and Technology<\/a> (NIST).<\/p>\n In early 2025, special signals wended their way through a fiber-optic highway strung above the streets and sidewalks of the Maryland suburbs. The arrival of those signals at their destination marks a significant step toward a long-held dream of building a \u201cquantum network.\u201d Researchers believe that this emerging technology could someday link quantum devices in ways that supercharge scientific research, enable ultrasecure communications and boost the power of future quantum computers.<\/p>\n National Institute of Standards and Technology<\/a> (NIST) researchers and collaborators\u00a0reported this advance<\/a>\u00a0in the\u00a0Journal of Optical Communications and Networking.<\/p>\n A Special Kind of Network\u00a0<\/p>\n Quantum networks depend on a special phenomenon called entanglement. Often described as \u201cspooky action at a distance\u201d (a translation of a phrase coined by Albert Einstein), entangled objects share a unified quantum state, meaning they cannot be described independently even if they are far apart. When one object from an entangled pair is measured, this action determines the results of a measurement made on the other.<\/p>\n These long-distance links could reshape fields from astronomy to seismology to drug discovery. By sharing entangled photons, telescopes thousands of kilometers apart could someday collect and combine light from the same distant star or planet, yielding a much sharper image than any one telescope could on its own. Entangled sensors spread over an area could \u201clisten\u201d for tiny seismic disturbances and pinpoint a coming earthquake or volcanic eruption.<\/p>\n Networks of entangled quantum computers, meanwhile, might someday crunch algorithms too complex for any single device, helping scientists simulate potential new drugs and materials. Another possible application: ultrasecure communications networks where any attempt at hacking would be easily detected.<\/p>\n To unlock such benefits, however, scientists must first overcome multiple technical challenges. Among the biggest hurdles is finding a way to keep fragile entangled states alive outside the lab.\u00a0<\/p>\n Quantum networks gain their power by connecting distant users. But building entire fiber networks just for quantum applications would be prohibitively expensive. So a team of researchers from NIST, the Joint Quantum Institute (a partnership between NIST and the University of Maryland) and the New York-based company Qunnect set out to test whether quantum networks can run on the existing fiber-optic infrastructure that powers today\u2019s internet.<\/p>\n \u2018About as Bad a Connection as You Can Possibly Have\u2019<\/p>\n Most of the fibers the researchers used in their study dangle from poles. They expand as temperatures rise during the day and contract at night. Wind blows them around, and birds land on them. All these things can distort entangled photons as they propagate through the fibers.<\/p>\n \u201cIt\u2019s about as bad a connection as you can possibly have,\u201d said NIST physicist Oliver Slattery, one of the authors of the new study.<\/p>\n A noisy environment doesn\u2019t trouble the so-called classical networks that carry your phone calls, video streams, emails and so on. In classical communication, information is typically encoded by modulating the power of the transmitted light, which is not sensitive to mechanical disturbances or temperature changes.\u00a0<\/p>\n By contrast, noisy fibers can be a showstopper for quantum networking. That\u2019s because entangled states are usually encoded in what is known as photons\u2019 polarization \u2014 the direction along which their electric field vibrates.<\/p>\n As they expand, contract and sway in the wind, fibers can twist and distort the polarizations of photons traveling through them \u2014 potentially disrupting the delicate entangled states as well.<\/p>\n
![\"Entanglement:](\"https:\/\/www.newsbeep.com\/us\/wp-content\/uploads\/2026\/08\/Quantum-Entanglement-Final-sm.gif\")
<\/a>A pair of particles start out each in a quantum superposition of two energy states: state 0 and state 1. Because the particles are also entangled with each other, when one is measured (represented by a ruler), both must randomly \u201ccollapse\u201d such that one is fully in state 0 and the other is fully in state 1. The collapse is instantaneous for both particles, no matter how far apart they are.Credit:\u00a0N. Hanacek\/NIST<\/p>\n