Fluctuations and vortex pattern ordering in fully frustrated XY model with honeycomb lattice

S. E. Korshunov , Benoît Douçot (1)

1 LPTHE - Laboratoire de Physique Théorique et Hautes Energies

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.

Domaines: Autre [cond-mat.other]

S. E. Korshunov, Benoît Douçot. Fluctuations and vortex pattern ordering in fully frustrated XY model with honeycomb lattice. Physical Review Letters, 2004, 93, pp.097003. ⟨hal-00102564⟩