VORTEX ENTANGLEMENT AND BROKEN SYMMETRY

Based on the London approximation, we investigate numerically the stab ility of the elementary configurations of entanglement, the twisted pa ir and the twisted triplet, in the vortex-lattice and -liquid phases. We find that, except for the dilute limit, the twisted pair is unstabl e and hence irrelevant in the discussion of entanglement. In the latti ce phase the twisted triplet constitutes a metastable, confined config uration of high energy. Loss of lattice symmetry upon melting leads to deconfinement, and the twisted triplet turns into a low-energy helica l configuration.