Fluctuations and Vortex-Pattern Ordering in the Fully Frustrated XY Model on a Honeycomb Lattice
Abstract
The accidental degeneracy of various ground states of a fully frustrated XY model with a honeycomb lattice is shown to survive even when the free energy of the harmonic fluctuations is taken into account. The reason for that consists in the existence of a hidden gauge symmetry between the Hamiltonians describing the harmonic fluctuations in all these ground states. A particular vortex pattern is selected only when anharmonic fluctuations are taken into account. However, the observation of vortex ordering requires relatively large system size L≫Lc≳105.
- Publication:
-
Physical Review Letters
- Pub Date:
- August 2004
- DOI:
- 10.1103/PhysRevLett.93.097003
- arXiv:
- arXiv:cond-mat/0310536
- Bibcode:
- 2004PhRvL..93i7003K
- Keywords:
-
- 74.81.Fa;
- 05.20.-y;
- 64.60.Cn;
- Josephson junction arrays and wire networks;
- Classical statistical mechanics;
- Order-disorder transformations;
- statistical mechanics of model systems;
- Condensed Matter - Statistical Mechanics;
- Condensed Matter - Superconductivity
- E-Print:
- 4 pages, 2 figures, RevTeX4, a different method is used to find which state is selected by anharmonic fluctuations, the last third of the text is completly rewritten