Hund’s coupling and the metal-insulator transition in the two-band Hubbard model
Hund’s coupling and the metal-insulator transition in the two-band Hubbard model
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DOI：
10.1140/epjb/e2005-00117-4
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发表时间：
2004-11
期刊：
影响因子：
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通讯作者：
T. Pruschke;R. Bulla
中科院分区：
文献类型：
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作者：
T. Pruschke;R. Bulla
在动力学平均场理论下，在双带Hubbard模型中研究了Mott-Hubbard金属-绝缘体相变。为此，我们使用一个适当的扩展威尔逊的数值重整化群的有效双带单杂质安德森模型的解决方案。这种方法是非微扰的，特别是，允许考虑到充分交换的一部分，两个轨道之间的洪德规则耦合。我们详细讨论了各种库仑相互作用对热力学和动力学性质的影响，对于杂质和晶格模型。Hund规则耦合的交换部分对双带Hubbard模型的物理和Mott跃迁的性质起着重要的作用。
The Mott-Hubbard metal-insulator transition is investigated in a two-band Hubbard model within dynamical mean-field theory. To this end, we use a suitable extension of Wilson’s numerical renormalization group for the solution of the effective two-band single-impurity Anderson model. This method is non-perturbative and, in particular, allows to take into account the full exchange part of the Hund’s rule coupling between the two orbitals. We discuss in detail the influence of the various Coulomb interactions on thermodynamic and dynamic properties, for both the impurity and the lattice model. The exchange part of the Hund’s rule coupling turns out to play an important role for the physics of the two-band Hubbard model and for the nature of the Mott-transition.