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Classical Circular Polarization vs. Photon Spin Eigenstates

  1. Nov 18, 2014 #1

    referframe

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    Hello,

    Given an electromagnetic wave that is, from a classical point-of-view, not circular polarized. Does that correspond in QM to photons with the ZERO spin eigenstate?

    Thanks in advance.
     
  2. jcsd
  3. Nov 18, 2014 #2

    Orodruin

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    Photons do not have a spin 0 eigenstate, since they are massless spin 1 particles. Also be very careful in trying to treat classical fields as photons. Classical fields are generally described by coherent quantum states and not states carrying a particular number of photons.
     
  4. Nov 18, 2014 #3

    Avodyne

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    No, it corresponds to a superposition of states with spin +1 and -1, just like the classical wave can be written as a superposition (sum) of circularly polarized waves.
     
  5. Nov 18, 2014 #4

    referframe

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    So, by "spin +1" and "-1", are you referring to 2 of the 3 eigenvalues of the spin 1 operator/matrix for the Z direction?
     
  6. Nov 19, 2014 #5

    Orodruin

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    This is the thing, a massless spin 1 particle has only 2 eigenstates.
     
  7. Nov 19, 2014 #6

    referframe

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    I just got it. Thank you both.
     
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