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Quantum optics is a reference to a c-number

  1. Mar 23, 2012 #1
    quantum optics is a reference to a "c-number"


    In my lecture notes on quantum optics is a reference to a "c-number" electric field, and it is stated that, since it is a c-number, there is no corresponding Hamiltonian. As far as I have understood, a c-number is a classical value of some (possibly quantum mechanical) quantity. However, how can this rule out that the c-number has a Hamiltonian? E.g., a classical electric field has a well-defined Hamiltonian given by its energy density.

  2. jcsd
  3. Mar 23, 2012 #2


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    Re: c-number

    Niles, This would be an approximation, in which the degrees of freedom of the electric field are ignored and the field is treated as a constant external quantity maintained by a classical source.
  4. Mar 24, 2012 #3
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