Effective Heisenberg Model and Exchange Interaction for Strongly Correlated Systems.
Effective Heisenberg Model and Exchange Interaction for Strongly Correlated Systems.
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DOI：
10.1103/physrevlett.121.037204
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发表时间：
2018-02
影响因子：
8.6
通讯作者：
E. Stepanov;E. Stepanov;Sergey Brener;F. Krien;M. Harland;A. Lichtenstein;A. Lichtenstein;M. Katsnelson;M. Katsnelson
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文献类型：
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作者：
E. Stepanov;E. Stepanov;Sergey Brener;F. Krien;M. Harland;A. Lichtenstein;A. Lichtenstein;M. Katsnelson;M. Katsnelson
我们考虑了扩展的Hubbard模型，并引入了相应的用自旋算符表示的类Heisenberg问题。导出的形式主义让人想起安德森的有效交换相互作用的思想，并考虑了非局域关联效应。磁相中的交换相互作用和自旋磁化率的结果用单粒子量表示。这一事实不仅可以用于多带系统的实际计算，而且还允许我们重新考虑在最有趣的物理区域中对多体效应的一般描述，其中系统的物理性质由集体(玻色)涨落主导。在强自旋极化极限下，当局域磁矩定义良好时，交换相互作用简化为密度泛函理论的标准表达式，该理论已成功地用于实际材料的磁性计算。
We consider the extended Hubbard model and introduce a corresponding Heisenberg-like problem written in terms of spin operators. The derived formalism is reminiscent of Anderson's idea of the effective exchange interaction and takes into account nonlocal correlation effects. The results for the exchange interaction and spin susceptibility in the magnetic phase are expressed in terms of single-particle quantities. This fact not only can be used for realistic calculations of multiband systems but also allows us to reconsider a general description of many-body effects in the most interesting physical regimes, where the physical properties of the system are dominated by collective (bosonic) fluctuations. In the strongly spin-polarized limit, when the local magnetic moment is well defined, the exchange interaction reduces to a standard expression of the density functional theory that has been successfully used in practical calculations of magnetic properties of real materials.