Order as a consequence of disorder in frustrated Ising models

Abstract

The main interest of the domino model is to be tractable by analytic methods. Its properties are only of interest if they have some generality. i) Temperature-induced order is probably a fairly common property. In particular it may be expected in three-dimensional systems with ground state entropy proportional to N^1/3, from low-temperature expansions. It is probably more exceptional in two-dimensional systems. ii) Order induced by stoechiometric disorder is probably exceptional in Ising models. The domino model seems to be very spec.ial. iii) The fact that X″ can be strictly smaller than the concentration threshold X is an interesting feature of the domino model. It would be of interest to consider this possibility in other frustrated systems.

Of course the fact that thermal, stoechiometric (or quantum) disorder can produce magnetic order in Ising models is contrary to intuition. This is the main motivation of this communication, which is quite marginal in this Conference.