ar X iv : c on d - m at / 9 51 10 70 v 1 1 4 N ov 1 99 5 Phase Transitions of the Bilayered Spin - S Heisenberg Model and Its Extension to Fractional Dimensions
نویسنده
چکیده
We study the ground state and the phase transitions of the bilayered spinS antiferromagnetic Heisenberg model using the Schwinger boson mean field theory. The interplane coupling initially stabilizes but eventually destroys the long-range antiferromagnetic order. The transition to the disordered state is continuous for small S, and first order for large S. The latter is consistent with an argument based on the spin wave theory. The phase diagram and phase transitions in corresponding model in fractional dimensions are also discussed. PACS numbers: 75.10.J, 75.30.K, 75.40mg Typeset using REVTEX 1
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تاریخ انتشار 1995