M ar 1 99 6 Spin Diffusion in 2 D XY Ferromagnet with Dipolar Interaction

ar X iv : c on d - m at / 9 60 31 90 v 1 2 9 M ar 1 99 6 The Four - Dimensional XY Spin Glass

ar X iv : c on d - m at / 9 90 83 26 v 1 2 4 A ug 1 99 9 Gaudin Hypothesis for the XY Z Spin Chain

The XY Z spin chain is considered in the framework of the generalized algebraic Bethe ansatz developed by Takhtajan and Faddeev. The sum of norms of the Bethe vectors is computed and expressed in the form of a Jacobian. This result corresponds to the Gaudin hypothesis for the XY Z spin chain.

ar X iv : c on d - m at / 9 90 83 26 v 3 2 N ov 1 99 9 Gaudin Hypothesis for the XY Z Spin Chain

The XY Z spin chain is considered in the framework of the generalized algebraic Bethe ansatz developed by Takhtajan and Faddeev. The sum of norms of the Bethe vectors is computed and expressed in the form of a Jacobian. This result corresponds to the Gaudin hypothesis for the XY Z spin chain.

1 5 M ay 2 00 1 Exact diagonalization of the S = 1 / 2 XY ferromagnet on finite bcc lattices to estimate T = 0 properties on the infinite lattice

In this paper finite bcc lattices are defined by a triple of vectors in two different ways upper triangular lattice form and compact form. In Appendix A are lists of some 260 distinct and useful bcc lattices of 9 to 32 vertices. The energy and magnetization of the S = 1/2 XY ferromagnet have been computed on these bcc lattices in the lowest states for Sz = 0, 1/2, 1 and 3/2. These data are stud...

X iv : c on d - m at / 9 60 41 90 v 1 1 M ay 1 99 6 Circular phase of a two dimensional ferromagnet with dipolar interactions

We make for the first time a large-scale Monte-Carlo simulation of a fer-romagnetic Heisenberg model with dipolar interactions on a two dimensional square lattice with open boundaries using an efficient new technique. We find that a phase transition occurs in the model and the ordered phase is characterized by a circular arrangement of the spins.