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Quantum communications

  1. May 10, 2017 #1
    Lets suppose for SF story purposes, that the article is right that claims direct "counterfactual" communication through entanglement became possible, without classical communication channel.
    How should i portray that option? If information sent by detecting when, in which phase coherence is broken, coherence still broken, no more messages with that entangled pair.
    Should it be only used for emergency call? Should they build a big particle pair generator between Earth and Mars to achieve a narrow bandwith for most important messages that should delivered instantly? But most communications still done by radio.
     
  2. jcsd
  3. May 10, 2017 #2

    Ryan_m_b

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    What article?

    One of the most interesting fictional interpretations of entanglement communication I can think of is from Singularity Sky (and its sequel). In the book entangled q-bits allow for instantaneous communication but upon use are destroyed. Agents and organisations with chips of them have a diminishing amount of bandwidth, once it's all gone they have to get more. Additionally FTL travel broke the entanglement so chips carrying a few petabytes have to be sent by laser driven starwisp years in advance.
     
  4. May 10, 2017 #3
    Wouldn't the whole premise of FTL communications mean such a receiver of the same intelligence be at the other end? How would this happen with the distances involved. Great for SF but nothing else unless in our time line or near space, ie our solar system.
     
  5. May 10, 2017 #4
    That article :
    https://phys.org/news/2017-05-counterfactual-quantum.html
    https://www.sciencealert.com/scient...tual-quantum-communication-for-the-first-time
    http://www.pnas.org/content/114/19/4920.abstract

    That Singularity Sky looks interesting, i thought something similar.

    Well, my other question, if they put an entangled particle generator between Mars and Earth, is there any reasonable chance, that the particles remain entangled when they reach Earth and Mars? (simply radiate them can be enough? or has to pack them?)
     
  6. May 10, 2017 #5

    Ryan_m_b

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    Ok. I don't fully follow them but I don't think they've overturned the idea that information can't be transmitted faster than light. Isn't that what you're aiming for here? An FTL communication system for your SF story?

    I think entangled states are fragile though I'm not 100% sure. Packaging isn't a problem though if you're OK with the idea of interplanetary particle beams. Just pack a small chip carrying terrabytes of entangled particles into a few hundred gram micro-probe with a mag/light sail. A particle beam satellite on earth pushes it on a continual brachistochrone trajectory to Mars, half way its decelerated and captured by a Martian satellite.
     
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