SIMPLE VARIATIONAL WAVE-FUNCTIONS FOR TWO-DIMENSIONAL HEISENBERG SPIN-1/2 ANTIFERROMAGNETS
SIMPLE VARIATIONAL WAVE-FUNCTIONS FOR TWO-DIMENSIONAL HEISENBERG SPIN-1/2 ANTIFERROMAGNETS
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DOI：
10.1103/physrevlett.60.2531
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发表时间：
1988-06-13
影响因子：
8.6
通讯作者：
ELSER, V
中科院分区：
文献类型：
--
作者：
HUSE, DA;ELSER, V
我们概括了 Kasteleijn 和 Marshall 引入的一种变分波函数，包括长程相关性和非二分格。我们在三参数空间中找到了方晶格和三角晶格自旋 1/2 海森堡反铁磁体的最低能量波函数。这产生了这些系统基态能量的有用上限。波函数是完全明确的，因此可以通过蒙特卡罗技术轻松获得期望值的精确估计。看来反铁磁体在三角晶格以及方形晶格上都具有长程磁序。
We generalize a type of variational wave function introduced by Kasteleijn and Marshall, to include long-range correlations and nonbipartite lattices. We find the lowest-energy wave function in a three-parameter space for both the square-and triangular-lattice spin-½ Heisenberg antiferromagnets. This produces useful upper bounds on the ground-state energies of these systems. The wave functions are completely explicit, so that precise estimates of expectation values are readily obtained by Monte Carlo techniques. It appears that the antiferromagnet has long-range magnetic order on the triangular lattice, as well as on the square lattice.