Spin
An electron has no charge distribution, and is therefore considered a point charge. It does however produce a magnetic dipole that can be oriented in an external magnetic field, as with magnetic resonance. There is also a so called "current loop" that is created by the motion of the charged electron, despite its lack of any apparent volume which is required classically for such a current loop to exist. It also contributes to the total angular momentum the particle has, which is a sum of both the angular momentum and spin.
A particle's spin is generally represented in terms of spin operators. It turns out for particles that make up ordinary matter (protons, neutrons, electrons, quarks, etc.) particles are of spin 1/2, meaning that only two eigenvectors of the Hamiltonian exist for a spin 1/2 state, implying that there are only two values of energy that can be measured. Thus showing that the inherent quantum property of energy quantization is a direct result of electron spin.
Read more about this topic: Orbital Motion (quantum)
Famous quotes containing the word spin:
“In tragic life, God wot,
No villain need be! Passions spin the plot:
We are betrayed by what is false within.”
—George Meredith (1828–1909)
“Words can have no single fixed meaning. Like wayward electrons, they can spin away from their initial orbit and enter a wider magnetic field. No one owns them or has a proprietary right to dictate how they will be used.”
—David Lehman (b. 1948)