Comment by vi_sextus_vi

At a quick glance, I did not see the term "collapsed" in wiki. It isn't a collapse. (The concept is still relevant[0]!)

What was drawn like a "defined spin" for pedagogy should only have been coloured different. The lone spins are always part of a longer-range quantum superposition, maybe better represented as blue blobs. The lowest "excitations" are (superpositions of) triplets, for example.

Btw I put quotes around excitations because you touched on a mysterious aspect of these systems called the "spin gap". TFA mentions it. They don't even know whether this spin gap exists! Indeed, the term "liquid" means there might not be a spin gap. (It'd be best to colour the singlet blobs orange-red and the triplet blobs red-orange)

[0] In your parlance, a "collapse" literally means dropping to a macroscopic ground state across a gap, but a liquid is already "arbitrarily" close to the ground state. "Collapsing into defined spins" will take the system _out_ of the ground state, so it can't happen spontaneously... Or so it's believed..