Hi I am reading about quantization of orbital angular momentum and, as I read, I am trying to compare it to the theory I already know on how atoms behave in magnetic fields. Here is the situation so far (I only look at 1-electron atoms to keep it simple for now): I assume the quantization axis is along z, i.e. a magnetic field points this way. Say the atom is in a state such that m=1 in the magnetic field (an excited state), i.e. the projection of its angular momentum onto the Lz-axis is (h/2π) -- so this means that there is a nonzero angle between the dipole moment of the atom and the B-field. If I now turn off the magnetic field, the orientation of μ (the magnetic moment) is lost. If I then apply the magnetic field again (non-adiabatically), then what determines which state the atom ends up in? Best, Niles.