Later this summer, physicists at the Argonne and Fermi national laboratories will exchange quantum information across 30 miles of optical fiber running beneath the suburbs of Chicago. One lab will generate a pair of entangled photons—particles that have identical states and are linked in such a way that what happens to one happens to the other—and send them to their colleagues at the other lab, who will extract the quantum information carried by these particles of light. By establishing this two-way link, the labs will become the first nodes in what the researchers hope will one day be a quantum internet linking quantum computers around the nation.
A quantum web is loaded with potential. It would enable ultra-secure data transmission through quantum encryption. Astronomers could study distant galaxies in unprecedented detail by combining the rare intergalactic photons collected by individual optical telescopes to create a distributed superscope. Linking small quantum computers could create a quantum cloud and rapidly scale our computing abilities. The problem is that quantum information hates long-distance travel. Send entangled photons out into the real world through optical fiber and, in less than 50 miles, environmental interference will destroy their quantum state. But if the photons were relayed through a satellite instead, they could be sent to destinations hundreds—and potentially thousands—of miles away. So in 2018, NASA partnered with MIT’s Lincoln Laboratory to develop the technologies needed to make it happen.
The goal of the National Space Quantum Laboratory program, sometimes referred to as Quantum Technology in Space, is to use a laser system on the International Space Station to exchange quantum information between two devices on Earth without a physical link. The refrigerator-sized module would be attached to the outside of the space station and would generate the entangled photons that carry the quantum information to Earth. The demonstration would pave the way for a satellite that could take entangled particles generated in local quantum networks and send them to far-flung locations.
“In the future, we will likely see quantum information from Argonne routed through a sequence of satellites to another location across the country, or the world,” says David Awschalom, a senior scientist and the quantum group leader at Argonne National Laboratory. “Much like with existing telecommunications, developing a global quantum network may involve a combination of space- and ground-based platforms.”
Read more at WIRED.