* <Stern-Gerlach experiment>
* <fine structure> split in energy levels
* <anomalous Zeeman effect>
* of a more statistical nature, but therefore also macroscopic and more dramatically observable:
  * <ferromagnetism>
  * <Bose-Einstein statistics> vs <Fermi-Dirac statistics>. A notable example is the difference in <superfluid> transition <temperature> between <superfluid helium-3> and <superfluid helium-4>.


Spin experiments

{tag=1996 Nobel Prize in Physics}
{title2=observed 1972}
{wiki}

Surprisingly, it can also become a <superfluid> even though each atom is a <fermion>! This is because of <Cooper pair> formation, just like in <superconductors>, but the transition happens at lower temperatures than <superfluid helium-4>, which is a <boson>.

https://aps.org/publications/apsnews/202110/history.cfm[]: October 1972: Publication of Discovery of Superfluid Helium-3 contains comments on the seminal paper and a graph which we must steal.


Ciro Santilli @cirosantilli 37

 Incoming links: Superfluid helium-3