Dyadic models and magnetic order

Terry Tao gives a whirlwind tour of dyadic models:

… an important toy model for the line (in any of its incarnations), in which the geometric and algebraic structures are enhanced (and become neatly nested and recursive), at the expense of the one-dimensional structure (which is largely destroyed).

In Science, Xu et al talk about another one-dimensional object, namely a spin liquid due to a one-dimensional spin chain, and their discovery of a long range order (of coherence lengths of the order of 30 20 nanometres or so) in such systems.

The Science Blog post from which I learnt about this work has a nice introduction to the paper too; however, the post simply mentions “quantum” order, and does not describe the mechanism underlying the ordering. I have to read the paper carefully to figure that one out (which is not going to happen in the near future).

Happy reading!