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Double Slit Experiment

  1. Dec 27, 2013 #1
    What happen if I send electron 1 at a time and I use a detector but my detector don't show result neither record it (I setup it that way)? I presume the interference pattern is destroyed since the detector detect in which slit the electron go ? Do I am correct?
  2. jcsd
  3. Dec 27, 2013 #2


    Staff: Mentor

    It's got nothing to do if the detector shows or not shows a result - rather if it decoheres the photon or not. The interference pattern will be destroyed.

  4. Dec 28, 2013 #3


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    Gold Member

    If the detector does not show anything, the only way to know if it is really a detector is to look at the fringes!

    You may consider the setup "detector + screen as a setup used to measure the efficiency of the detector.
  5. Dec 28, 2013 #4
    How the detector work ? Precisely what in the detector makes the electron decoheres or not ?
  6. Dec 28, 2013 #5


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    Staff Emeritus
    Science Advisor
    Education Advisor

    I strongly recommend a recent paper in AJP that practically addressed all of this issue: Rueckner and Peidle, Am. J. Phys. v.81, p.951 (2013).

    The Introduction describes the experiment being reported:

    So even if one doesn't actually look at the measurement, the mere fact that one can actually do that after the fact is sufficient to affect the outcome of the result.

    Note that this setup being reported are suitable for advanced undergraduate labs. This demo has become THAT common.

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