Quantum Mechanics
Stern-Gerlach: Silver atoms
The magnetic moment of a silver atom is that of the spin of an electron. The inhomogeneous magnetic field deflects atoms with spin up and spin down in different directions. The atom is neutral and therefore there is no Lorentz force acting on it. The animation shows a superposition of wave packets with spin up (blue) and spin down (green) moving in an inhomogeneous magnetic field perpendicular to the plane of motion.
The field causes an actual separation in space of the spin up and spin down components of the initial wave packet.