Journal of Physics C Solid State Physics
Note on universality and the eight-vertex model
K Jungling, Gustav M. Obermair
Abstract
It is shown that the critical behaviour of the general eight-vertex model is equal to that of an Ising model with only two-spin interactions between first, second and third neighbours. The critical exponents of the latter must therefore, in general, depend on the ratios of coupling constants as those of Baxter's eight-vertex model have been shown to do, in contrast to universality so far assumed to hold for all short-range two-spin interactions.