The BEG Model in the Disordered Region and at the Antiquadrupolar-Disordered Line of Parameters

摘要

We analyse the d-dimensional BEG model with d >= 2 and parameters in the disordered region and at the antiquadrupolar-disordered line. We obtain a subset of these regions for which the odd correlation functions are zero and the even ones decay exponentially fast, at all non-zero temperatures, for a wide class of boundary conditions.