Answer to Question #101019 in Quantum Mechanics for SAHIL

Question

Explain all about. STERN- GERLACH EXPERIMENT .

What does it show?

its classical part & quantum part ?

How does it tell about spin half particles?

Answer 1

The Stern–Gerlach experiment demonstrated that the spatial orientation of angular momentum is quantized. Thus an atomic-scale system was shown to have intrinsically quantum properties. In the original experiment, silver atoms were sent through a spatially varying magnetic field, which deflected them before they struck a detector screen, such as a glass slide. Particles with non-zero magnetic moment are deflected, due to the magnetic field gradient, from a straight path. The screen reveals discrete points of accumulation, rather than a continuous distribution, owing to their quantized spin.

The experiment represents a direct measurement of one component of the spin of the electron,

this component being determined by the direction of the magnetic field, here taken to be in the z

direction.

There are two possible values for Sz, corresponding to the two spots on the observation screen, as

required by the fact that s = 1/2 for electrons, i.e. they are spin -1/2 particles. The allowed values for

the z component of spin are

Sz = ±1/2h