On the phase diagram of the discrete $Z_6$ spin models

Abstract

We point out some problems with the previously-proposed phase diagram of the $Z_6$ spin models. Consideration of the diagram near to the decoupling surface using both exact and approximate arguments suggests a modification which remedies these deficiencies. With the aid of a new parametrisation of the phase space, we study the models numerically, with results which support our conjectures.

Comments: 10 pages, Latex 2e, 4 figures, uses epsf, amssymb, cite