Magnetic & electric fields in QM?

[pivoxa15]

All atoms have magnetic moments but does Quantum theory require magnetic fields at all?

Does Quantum theory require electric fields?

 

[dextercioby]

In QM the potentials are the fundamental objects, as compared to the classical electrodynamics where the fields are measurable and viewed as fundamental, while the potential are only mathematically convenient objects.

 

[pivoxa15]

I know the magnetic moment is important in QM such as the Bohr magneton. But you could say that it is used to calculate the magnetic potential energy.

 

[dextercioby]

The magnetic moment is one thing, the magnetic potential $\mathbf{A}$ is another. And the Bohr magneton is just a number (it had been previously introduced in 1912 by the Romanian physicist Stefan Procopiu). And the magnetic potential energy is usually the potential interaction energy b/w an external magnetic field and a dipole. So you need to to brush up your knowledge of these concepts.