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arXiv · 1411.0789

Absence of a classical long-range order in $S=1/2$ Heisenberg antiferromagnet on triangular lattice

Nobuo Suzuki·Fumitaka Matsubara·Sumiyoshi Fujiki·Takayuki Shirakura
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Abstract

We study the quantum phase transition of an $S=1/2$ anisotropic $\alpha$ $(\equiv J_z/J_{xy})$ Heisenberg antiferromagnet on a triangular lattice. We calculate the sublattice magnetization and the long-range helical order-parameter and their Binder ratios on finite systems with $N \leq 36$ sites. The $N$ dependence of the Binder ratios reveals that the classical 120$^{\circ}$ N\'{e}el state occurs for $\alpha \lesssim 0.55$, whereas a critical collinear state occurs for $1/\alpha \lesssim 0.6$. This result is at odds with a widely-held belief that the ground state of a Heisenberg antiferromagnet is the 120$^{\circ}$ N\'{e}el state, but it also provides a possible mechanism explaining experimentally observed spin liquids.

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Nobuo Suzuki, Fumitaka Matsubara, Sumiyoshi Fujiki, Takayuki Shirakura. 2014-11-04. Absence of a classical long-range order in $S=1/2$ Heisenberg antiferromagnet on triangular lattice. https://doi.org/10.1103/physrevb.90.184414

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