Fluctuations and vortex pattern ordering in fully frustrated XY model with honeycomb lattice
arXiv:cond-mat/0310536 · doi:10.1103/PhysRevLett.93.097003
Abstract
The accidental degeneracy of various ground states in 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>>100000.
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