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arXiv · 0909.0121

Z_2-vortex ordering of the triangular-lattice Heisenberg antiferromagnet

Hikaru Kawamura·Atsushi Yamamoto·Tsuyoshi Okubo
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Abstract

Ordering of the classical Heisenberg antiferromagnet on the triangular lattice is studied by means of a mean-field calculation, a scaling argument and a Monte Carlo simulation, with special attention to its vortex degree of freedom. The model exhibits a thermodynamic transition driven by the Z_2-vortex binding-unbinding, at which various thermodynamic quantities exhibit an essential singularity. The low-temperature state is a "spin-gel" state with a long but finite spin correlation length where the ergodicity is broken topologically. Implications to recent experiments on triangular-lattice Heisenberg antiferromagnets are discussed.

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Hikaru Kawamura, Atsushi Yamamoto, Tsuyoshi Okubo. 2010-06-19. Z_2-vortex ordering of the triangular-lattice Heisenberg antiferromagnet. https://doi.org/10.1143/jpsj.79.023701

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