BILAYERED SPIN-S HEISENBERG-MODEL IN FRACTIONAL DIMENSIONS

The ground state and the phase transitions of the bilayered spin-S ant i-ferromagnetic Heisenberg model were stuided by Ng et al.(1) by using the Schwinger boson mean field theory. In this paper, an analytic con tinuation of the self-consistent equations is carried out in order to study the extension of the model to fractional dimensions from 1 to 2. Decreasing the dimensionality from 2 has an effect similar to that of decreasing the spin S. The corresponding phase diagram and phase tran sition will also be discussed.