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Duality principle is 'safe and sound'

  1. Aug 26, 2014 #1

    It seems an experiment was performed back in 2012 that measured which-way information, but also found interference. (I may have come across it at the time, but cannot recall reading about it from memory.) How could this be so?
    However, as the article states, Robert Boyd found out the cause of this:
  2. jcsd
  3. Aug 27, 2014 #2


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    That is an incredibly annoying way of overselling.

    The 2012 paper (R. Menzel, D. Puhlmann, A. Heuer, and W. P. Schleich.
    Wave-particle dualism and complementarity unraveled by
    a dierent mode. Proceedings of the National Academy of
    Sciences, 109(24):9314{9319, 2012., http://www.pnas.org/content/109/24/9314.abstract?sid=af26123d-7825-4b52-bdae-beab95cf46f9) never actually claimed that it breaks complementarity or stuff like that. They had two modes of different wave vector present at the double slit, which means that even if you only have one slit, you still have two probability amplitudes for getting a photon to the detector that can interfere, if it is intrinsically indistinguishable which mode each photon will end up in.

    The current paper (http://arxiv.org/abs/1402.6487) now shows that the previous paper does not prove a claim that was never made in that paper. I need to remember that trick for "selling" my next manuscripts. I must admit that their analysis of interference visibility variations is nice. I am still somewhat puzzled why the paper made it to PNAS, though.
    Last edited: Aug 27, 2014
  4. Aug 27, 2014 #3
  5. Feb 24, 2017 #4
    Hey I was just talking about the same article and how they found which path the photon took while obtaining an interference pattern. So it turns out that they don't? is that what the new article is saying?
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