Advance opens door for secure quantum applications without specialized infrastructure

  • partial_accumen@lemmy.world
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    21 hours ago

    Yes. Keep in mind nothing in the article talks about the fiber repeater. That is my addition with some knowledge of telecommunications infrastructure. Because fiber optic cable isn’t perfect, there is light loss over distance. Different grades of fiber have different levels of loss across distance. An example of high end fiber would be ZBLAN. There is experimental level manufacturing (successful in small quantities already) of producing ZBLAN fiber in space to improve the fiber quality, but that makes it much more expensive. Once the limits of the fiber are reached a telecommunications provider can place a fiber repeater to double the length by intercepting the light (signal) and reproducing it (blinking new laser light) into the next segment of fiber.

    However, these repeaters create NEW light, and that would mean the quantum information is not carried over in present day fiber repeaters. Even measuring the entangled photon to recreate it would break the quantum state of the entangled photon at the source, so current means can’t be used as a repeater for quantum data.