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Coherent interaction

  1. Jan 14, 2014 #1
    Hi! I would really appreciate you to help me answer this question:

    What is the physical meaning of coherent interaction (in the Dicke model for example)?

    I mean, coherence is well defined in classical optics, but what does it means when you ask for a system of N atomic dipoles to interact coherently with an electromagnetic field? :confused:

  2. jcsd
  3. Mar 11, 2015 #2
    I'm not sure but I suppose it means that the N dipoles are all interacting with the field while in phase with each other.

    I don't know about the Dicke model, as I'm struggling to understand Dickes papers, but for a system interacting with field :
    E=A cos(kx-ωt)
    Assume that the wavelength of E is large enough that all N dipoles see ~ the same E,
    E=A cos(ωt)
    Then coherent if the response of the dipoles is the same and has the same time evolution,
    Dipole 1 has moment
    P1 = e cos(ωt)
    Same as dipole 2
    P2= e cos(ωt)
    If they interacted incoherently then
    P2= e cos(ωt + p(t))
    Where p(t) is some time varying phase difference in the dipoles responce.
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