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arXiv · 0801.3217

Uniaxially anisotropic antiferromagnets in a field on a square lattice

M. Holtschneider·W. Selke
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Abstract

Classical uniaxially anisotropic Heisenberg and XY antiferromagnets in a field along the easy axis on a square lattice are analysed, applying ground state considerations and Monte Carlo techniques. The models are known to display antiferromagnetic and spin-flop phases. In the Heisenberg case, a single-ion anisotropy is added to the XXZ antiferromagnet, enhancing or competing with the uniaxial exchange anisotropy. Its effect on the stability of non-collinear structures of biconical type is studied. In the case of the anisotropic XY antiferromagnet, the transition region between the antiferromagnetic and spin-flop phases is found to be dominated by degenerate bidirectional fluctuations. The phase diagram is observed to resemble closely that of the XXZ antiferromagnet without single-ion anisotropy.

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M. Holtschneider, W. Selke. 2008-01-21. Uniaxially anisotropic antiferromagnets in a field on a square lattice. https://doi.org/10.1140/epjb/e2008-00149-2

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