Charge dynamics of correlated electrons: Variational description with inclusion of composite fermions
Charge dynamics of correlated electrons: Variational description with inclusion of composite fermions
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DOI：
10.1103/physrevb.101.075124
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发表时间：
2019-07
影响因子：
3.7
通讯作者：
Kota Ido;M. Imada;Takahiro Misawa
中科院分区：
文献类型：
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作者：
Kota Ido;M. Imada;Takahiro Misawa
提出了一种基于变分蒙特卡罗方法计算相关电子系统基态电荷动态结构因子的方法。我们对一维和二维Hubbard模型的基准测试表明，在基集中包含复合费米子激励大大提高了精度，参考了团簇的精确电荷动态结构因素。我们的研究结果表明，如果复合费米子激发在线性响应理论的中间态的有限希尔伯特空间中适当地包含，变分蒙特卡罗方法是研究相关材料（如氧化铜超导体）中电荷动力学性质的一种很有前途的方法。我们还讨论了引入非定域复合费米子对更精确描述的重要性。
We propose a method to calculate the charge dynamical structure factors for the ground states of correlated electron systems based on the variational Monte Carlo method. Our benchmarks for the one- and two-dimensional Hubbard models show that inclusion of composite-fermion excitations in the basis set greatly improves the accuracy, in reference to the exact charge dynamical structure factors for clusters. Together with examination for larger systems beyond tractable sizes by the exact diagonalization, our results indicate that the variational Monte Carlo method is a promising way for studies on the nature of charge dynamics in correlated materials such as the copper oxide superconductors, if the composite-fermion excitations are properly included in the restricted Hilbert space of intermediate states in the linear response theory. We also discuss the importance of incorporating nonlocal composite fermion for more accurate description.