On the quantum-mechanical description of the Stern-Gerlach experiment

Although the Stern-Gerlach experiment is very important both in atomic physics and as an example of a quantum process of measurement, we do not find in the literature a convincing theoretical analysis of this phenomenon. We present here a detailed quantum description of that experiment for hydrogen atoms or alkali atoms. The conclusion is that, considering the approach where the spin-orbit coupling is disregarded, the experiment makes in fact possible to determine the component of atomic magnetic moment along the field direction. The results obtained can also prove two of the basic postulates of quantum mechanics