QuantumPhysics.dvi

(Wang) #1

Figure 4: The Stern-Gerlach apparatus


SG deals with measuringS, or equivalentlym. To measurem, we place it in a magnetic


fieldB, which produces an energy dependenceEand a forceFon the electron, given by


E=−m·B F=∇~(m·B) (2.22)


Thus, a magnetic moment placed in an inhomogeneous magnetic field willexperience a force,


which will lead to bending of the trajectory and is observable. To create an inhomogeneous


magnetic field, one uses asymmetrical poles, as in the figure above. Henceforth, the entire


SG apparatus will simply be represented by a box, as in the figure. A beam of neutral silver


atoms is now sent trough the SG apparatus (along thex-axis) and the signal is received on


a screen placed perpendicularly to the beam.


Figure 5: The Stern-Gerlach experimental set-up


The experimental outcomes are as follows,

Free download pdf