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Effect for time lag in quantum erasure?

  1. Apr 15, 2010 #1
    When which way information is erased, interference reappears. Is there any theoretical
    and experimentally confirmed evidence that the interval between pair creation and erasure
    has any effect? The experiments i've read seem more concerned with evidencing the
    erasure and delayed erasure result rather than mapping interference differences alomg
    the full length of the idler arm.
  2. jcsd
  3. Apr 15, 2010 #2


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    Welcome to PhysicsForums, madison!

    There have been sensitive experiments to determine if entanglement occurs in a finite amount of time - and it appears to be instantaneous (at least 10,000 times c). Not sure if that is in effect what you are asking, but there does not seem to be anything detectible regarding ordering of observing Alice or Bob.
  4. Apr 15, 2010 #3
    yes i think this answers my question. In quantum erasure and delayed erasure experiments
    I conclude that erasure of which way information - either before or after negotiating
    2 slits- restores interference.

    It does not matter whether erasure happens first or interference happens first, knowledge
    (future or past) is enough and at the speeds you quote then that information is instantaneous.

    Thanks for your help.
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