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Wave particle duality as applied to photon

  1. Oct 9, 2009 #1
    so basically a wave particle duality principle state that sometimes a "matter" would behave as a particle and a wave a another time. The was to reconcile this is through QM's statistical interpretation and the math construct is very obvious that such proposed matter is indeed a wave-particle in duality. The wave is a matter wave or probability wave.

    Now my question is, how about light, or photon. Is it an EM wave or a probability wave?
  2. jcsd
  3. Oct 9, 2009 #2


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    The situation with the photon is the same as with the "matter" particle like electron.
  4. Oct 9, 2009 #3


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    When we have a single photon (or a "few" of them) we must deal with it as a QM particle (which is different from a classical particle) in probabilistic terms.

    When we have bazillions and bazillions of photons, as we do in most "everyday" situations, we can describe their combined effects in terms of classical electromagnetic waves.
  5. Oct 9, 2009 #4


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    It is interesting to note that we cannot do that for matter particles, because matter particles are fermions so you cannot have many fermions in the same state. A more technical way to say this is that fermions cannot be in a coherent state.
  6. Oct 11, 2009 #5
    so, a single photon cannot be described as an EM wave?

    I mean I fully understand the idea that particle is a matter-wave. I am doing QM so it is pretty familiar.

    The problem is I that I cannot yet reconcile the idea that a matter wave is an EM wave as well. I have no idea what that means.
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