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Lifting of Multiphase Degeneracy by Quantum Fluctuations

A. B. Harris·C. Micheletti·J. M. Yeomans
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Abstract

We study the effect of quantum fluctuations on the multiphase point of the Heisenberg model with first- and second-neighbor competing interactions and strong uniaxial spin anisotropy $D$. By studying the structure of perturbation theory we show that the multiphase degeneracy which exists for $S=\infty$ (i.e., for the ANNNI model) is lifted and that the effect of quantum fluctuations is to stabilize a sequence of phases of wavelength 4,6,8,...~. This sequence is probably an infinite one. We also show that quantum fluctuations can mediate an infinite sequence of layering transitions through which an interface can unbind from a wall.

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A. B. Harris, C. Micheletti, J. M. Yeomans. 1995-05-04. Lifting of Multiphase Degeneracy by Quantum Fluctuations. https://doi.org/10.1103/physrevb.52.6684

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