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Huygens-Fresnel Principle in QM

  1. Jun 29, 2011 #1
    As far as explaining the refraction of light through glass (as an example), does the Huygens-Fresnel principle serve any purpose in the quantum mechanical (or the quantum electrodynamical) model?


    Is the Huygens Fresnel principle only useful in classical mechanics? If so, what IS used in the QM/QED model to explain refraction of light through differing media?
  2. jcsd
  3. Jun 30, 2011 #2
    You have to complete it with the principle of Fermat (Pierre de Fermat, 17e) : the real paths of a wave are those by which it arrives in phase with the neighbouring paths.
    Corrected by Young and Fresnel : If a path is dephased by a multiple of the wave length, it it still good. This is the interference phenomenon.

    In 1924, Broglie has stated that it is good too for material waves, say an electron. W.R. Hamilton had already established the formalism, but without any explanation of this coincidence, then (~1834).

    And later, Richard Feynman reinvented the Fermat's principle : The paths integrals.

    So Fermat, Huyghens and Fresnel are still fundamental in Quantum physics, because of its undulatory reality, because of the periodic character of every quanton.
    See for instance the Aharanov-Bohm type of experiments : the pattern of interference slides up or down, depending on the magnetic potential induced by a microsolenoïd between the two paths of each electron.
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