Lifting of Multiphase Degeneracy by Quantum Fluctuations

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.

55 pages ReVTeX (encoded with uufiles) + 17 uuencoded figures

References in corpus (3)

• Spin Softening in Models with Competing Interactions: A New High Anisotropy Expansion to All Orders
• The Role of Spin Anisotropy in the Unbinding of Interfaces
• Quantum Fluctuations in the Annni Model

Cited by in corpus (5)

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• Extended Quantum Dimer Model and novel valence-bond phases
• Quantum dimer models and exotic orders