Quantum optics is a reference to a c-number

[Niles]

quantum optics is a reference to a "c-number"

Hi

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.


Niles.

 

[Bill_K]

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.

 

[Niles]

Thanks. For the people wondering how to write the Hamiltonian of the classical field, please take a look here: https://www.physicsforums.com/showthread.php?t=580854