According to mechanics, the equation of motion of the spin J is: where μ is the magnetic moment.
g is g-factor, which is dimensionless and reflecting the environmental effect on the spin.
when turned on the rotating magnetic field (BR), with angular frequency ω.
By sweeping ωR, one can obtain a maximum flipping and determine the magnetic moment.
Select one beam (spin up state, for example) and let it pass the rotating field.