Variational Monte-Carlo Studies of Hubbard Model. I
Variational Monte-Carlo Studies of Hubbard Model. I
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DOI：
10.1143/jpsj.56.1490
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发表时间：
1987-04
影响因子：
1.7
通讯作者：
H. Yokoyama;H. Shiba
中科院分区：
文献类型：
--
作者：
H. Yokoyama;H. Shiba
作为前一篇论文的续篇[J.Phys.SoC。日本。56(1987)1490]，将变分蒙特卡罗方法推广到包括反铁磁长程序。该理论建立在古兹威尔关联因子的基础上，并用蒙特卡罗方法准确地考虑了关联因子的影响。给出了一维点阵(50个点阵)、二维正方点阵(20×20个点阵)和三维简立方点阵(6×6×6个点阵)的半充满带情况。这一结果与以往基于随机相位型“古兹维勒近似”的研究有质的不同。二维和三维的变分能量与赫希的量子蒙特卡罗数据进行了比较，结果令人满意。
As a continuation of a previous paper [J. Phys. Soc. Jpn. 56 (1987) 1490], the variational Monte-Carlo method is extended to include the antiferromagnetic long-range order. The theory is based on the Gutzwiller-type correlation factor and its effect is exactly taken into account by the Monte-Carlo procedure. An application is made to the half-filled-band case of one-dimensional lattice (50 sites), two-dimensional square lattice (up to 20×20 sites) and three-dimensional simple cubic lattice (6×6×6 sites). The result is qualitatively different from previous studies relying on the random-phase-type “Gutzwiller approximation.” The variational energy for two and three dimensions is favorably compared with Hirsch's quantum Monte-Carlo data.