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arXiv 1908.03979cond-mat.str-el
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利用基态么正变换将哈伯德模型映射到t-J模型

Mapping the Hubbard model to the t-J model using ground state unitary transformations

Yifan Tian

摘要:

哈伯德模型的有效低能模型通常由微扰理论导出。本文利用数值优化的幺正变换,导出了自旋空间和t-J空间中哈伯德模型的有效模型。我们将哈密顿量表示为矩阵乘积态(MPO),并根据张量网络方法使用门来表示幺正变换。我们通过优化哈伯德模型的基态和哈伯德模型的基态在自旋空间和t-J空间的投影之间的幺正变换得到了这个幺正变换。我们从数值优化得到的幺正变换产生有效的模型,符合微扰理论。这种从基态出发的数值优化方法为分析强关联电子系统的有效低能模型提供了另一种途径。

英文摘要:

The effective low-energy models of the Hubbard model are usually derived from perturbation theory. Here we derive the effective model of the Hubbard model in spin space and t-J space using a unitary transformation from numerical optimization. We represent the Hamiltonian as Matrix product state(MPO) and represent the unitary transformation using gates according to tensor network methods. We obtain this unitary transformation by optimizing the unitary transformation between the ground state of the Hubbard model and the projection of the Hubbard model ground state into spin space and t-J space. The unitary transformation we get from numerical optimization yields effective models that are in line with perturbation theories. This numerical optimization method starting from ground state provides another approach to analyze effective low-energy models of strongly correlated electron systems.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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