Unlike in the standard Fermi liquid model, the quantum mechanical spins of some electrons in the material are linked together in an FFL. (scientificamerican.com)
The aligned spins of electrons left a distinct sign when a beam of polarized light was reflected off the material's surface in ferromagnetic materials. (scienceworldreport.com)
An ionized hydrogen atom, consisting of a proton shorn of its associated electron, can not undergo the 21 - centimeter transition discussed above, since that transition depends on the relative spins of the electron - proton pair. (discovermagazine.com)