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Is There a Phase Transition in the Isotropic Heisenberg Antiferromagnet on the Triangular Lattice?

W. Stephan·B. W. Southern
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Abstract

The phase diagram of the classical anisotropic (XXZ) Heisenberg model on the 2-dimensional triangular lattice is investigated using Monte Carlo methods. In the easy-axis limit, two finite temperature vortex unbinding transitions have been observed. In the easy-plane limit, there also appear to be two distinct finite temperature phase transitions. The upper transition corresponds to an Ising-like chirality ordering and the lower temperature transition corresponds to a Kosterlitz-Thouless vortex unbinding transition. These phase transition lines all meet at the Heisenberg point and provide strong evidence that the isotropic model undergoes a novel finite temperature phase transition.

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W. Stephan, B. W. Southern. 2000-09-07. Is There a Phase Transition in the Isotropic Heisenberg Antiferromagnet on the Triangular Lattice?. https://doi.org/10.1139/cjp-79-11-12-1459

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