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… Expand

We construct a two-dimensional microscopic model of interacting quantum dimers that displays an infinite number of periodic striped phases in its T=0 phase diagram. The phases form an incomplete… Expand

Abstract Models with competing interactions, for example the ANNNI model, can have special points at which the ground state is infinitely degenerate, so-called multiphase points. Small perturbations… Expand

The Kugel-Khomskii (KK) Hamiltonian describes spin and orbital superexchange interactions between d 1 ions in an ideal cubic perovskite structure, in which the three t 2 g orbitals are degenerate in… Expand

We extend the quantum dimer model (QDM) introduced by Rokhsar and Kivelson so as to construct a concrete example of the model which exhibits the first-order phase transition between different… Expand