Duality principle is 'safe and sound'

In summary, the article states that an experiment was performed back in 2012 that found interference, but it was due to the fact that the Germans had accidentally sampled the sections of the double slit with greater probability than the other sections. The new article says that this does not prove that the wave-particle duality is invalid, as Boyd had previously claimed.
  • #1
StevieTNZ
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http://phys.org/news/2014-08-duality-principle-safe-apparent-violation.html

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?
In their 2012 version of the famous Young two-split experiment, Ralf Menzel and his colleagues at the University of Potsdam simultaneously determined a photon's path and observed high contrast interference fringes created by the interaction of waves from the two slits.

However, as the article states, Robert Boyd found out the cause of this:
Boyd and his colleagues discovered that the German physicists had inadvertently sampled the sections of high visibility with greater probability than the other sections. While only a handful of photons produced high visibility interference, they used the entire set of photons to determine the predictability of knowing through which slit they had passed.
 
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  • #2
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.
 
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  • #4
StevieTNZ said:
http://phys.org/news/2014-08-duality-principle-safe-apparent-violation.html

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:
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?
 

Related to Duality principle is 'safe and sound'

1. What is the duality principle?

The duality principle is a concept in physics that states that certain physical systems can be described equally well by two different mathematical formulations, known as dual descriptions.

2. Is the duality principle widely accepted in the scientific community?

Yes, the duality principle is a well-established concept in physics and is widely accepted by scientists. It has been extensively studied and confirmed through various experiments and theoretical models.

3. What is the significance of the duality principle?

The duality principle allows us to better understand and describe complex physical systems by providing different perspectives and mathematical tools to analyze them. It has also led to important breakthroughs in our understanding of fundamental physical laws, such as in the case of string theory.

4. Can the duality principle be applied to all physical systems?

No, the duality principle is not a universal concept and only applies to certain physical systems. It is most commonly observed in theories that involve symmetries and has been successfully applied to fields such as quantum mechanics and general relativity.

5. Is the duality principle 'safe and sound' in terms of its validity?

Yes, the duality principle has been extensively tested and confirmed by experiments and is considered a valid and reliable concept in physics. However, as with any scientific theory, it is always subject to further testing and refinement as our understanding of the universe evolves.

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