Circular polarization wrt. magnetic field

[Niles]

Hi

I am a little confused regarding circular polarization. I have attached a figure in order to explain the situation I have been thinking of: It shows (to the left) how a magnetic field changes from being positive to being negative. The arrow indicates my quantization axis. To the right I have sketched the incoming EM-light, and the circle indicates that it is circularly polarized. The direction is such that it is σ^- wrt. the quantization axis (the right hand rule).

The main objective is that I want to drive the Δm=-1 (from J=0, m=0 to J=1, m=-1) transition of an atom moving from left ro right. But this is the part that is troubling me: Am I allowed to just define the quantization axis the way I have? With this definition, the only thing that changes is the magnetic dipole moment of the atom, and it goes from negative to positive. Am I right in all this?

Thanks for any help in advance.


Niles.

 

[eljose79]

Hello Niles,

Thank you for your question. Circular polarization refers to the direction of the electric field in an electromagnetic wave. In your figure, the circularly polarized light is indicated by the circle, and the direction of the electric field is perpendicular to the direction of propagation.

In terms of your objective, it is possible to drive the Δm=-1 transition by defining the quantization axis as you have. This means that the magnetic dipole moment of the atom will change from negative to positive, as you have correctly stated. However, it is important to note that the quantization axis is arbitrary and can be defined in any direction. It is often chosen based on convenience or to align with the experimental setup.

I hope this helps clarify your understanding of circular polarization and its relation to defining the quantization axis. Let me know if you have any further questions.