We will derive the Hamiltonian terms added when an atom is put in a magnetic field in
section 20.
For now, we can be satisfied with the classical explanation that the circulating current
associated with nonzero angular momentum generates a magnetic moment, as does a classical
current loop.
This magnetic moment has the same interaction as in classical EM,
* Example:
The energy eigenstates of an system in a B-field.*
* Example:
Time development of a state in a B field.*
Jim Branson 2013-04-22