#### Magnetic resonance

This animation illustrates magnetic resonance, namely the evolution of a spin in
a strong magnetic field B_{0} submitted additionally to a rotating
magnetic field B_{1}, perpendicular to B_{0}. When the
frequency w of the rotating field is exactly equal to Larmor frequency, magnetic
resonance is achieved. The spin then goes slowly but surely from state
|-> to state |+>, and vice-versa. In contrast, if the frequency
of the rotating field is not tuned to Larmor frequency, < Sz > oscillates
only a tiny little bit aroung its average value (try for example
w/w_{0}=3.5).

Note that the field magnitudes are expressed in frequency units
according to the relations hbar w_{0} = g B_{0} and
hbar w_{1} = g B_{1}, where g is the gyromagnetic ratio.

**
Note that this version is obsolete. Please see the new version.
**