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Phase transition in a 2-dimensional Heisenberg model

Henk W. J. Bloete·Wenan Guo·Henk J. Hilhorst
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Abstract

We investigate the two-dimensional classical Heisenberg model with a nonlinear nearest-neighbor interaction V(s,s')=2K[(1+s.s')/2 ]^p. The analogous nonlinear interaction for the XY model was introduced by Domany, Schick, and Swendsen, who find that for large p the Kosterlitz-Thouless transition is preempted by a first-order transition. Here we show that, whereas the standard (p=1) Heisenberg model has no phase transition, for large enough p a first-order transition appears. Both phases have only short range order, but with a correlation length that jumps at the transition.

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Henk W. J. Bloete, Wenan Guo, Henk J. Hilhorst. 2002-01-11. Phase transition in a 2-dimensional Heisenberg model. https://doi.org/10.1103/physrevlett.88.047203

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