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EPR experiment with twin photons then interference experiment

  1. Jun 27, 2013 #1
    If we have twin photons moving in the opposite direction.

    For the first photon we can pass it through a polarizer that will either output a photon with vertical polarization or a photon with horizontal polarization.

    after this experiment we now know what will the other unobserved photon polarization will be if it passes through this polarizer (EPR paradox)

    My question is .. what will be the results if we used the unobserved photon in an interference experiment. will it produce an interference pattern ?
  2. jcsd
  3. Jun 27, 2013 #2


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    Staff: Mentor

    You'll have to tell us a lot more about what you mean by an "interference experiment", starting with what the particle will be interfering with.
  4. Jun 27, 2013 #3
    I am asking if it will interfere with it self. this single unobserved photon that we knew it's polarization by observing the polarization of it's twin. but the photon it self is unobserved.

    If we did this experiment multiple times. will there be an interference pattern ?
  5. Jun 27, 2013 #4


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    As it happens, the answer is NO. In the general case, entangled photons do not produce interference because they are not sufficiently coherent.

    See Zeilinger, page 290, figure 2, there is no direct interference pattern for entangled photons:

    Experiment and the foundations of quantum physics (1999)[/QUOTE]
  6. Jun 27, 2013 #5

    Thanks for the answer and the interesting link
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