Ferromagnetism in multiband Hubbard models: From weak to strong Coulomb repulsion.
Ferromagnetism in multiband Hubbard models: From weak to strong Coulomb repulsion.
复制标题
多带哈伯德模型中的铁磁性：从弱到强的库仑斥力。
DOI：
10.1103/physrevb.54.4056
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Takuya Tsukagoshi
中科院分区：
文献类型：
--
作者：
K. Penc;Hiroyuki Shiba;Fr'ed'eric Mila;Takuya Tsukagoshi
我们提出了一种机制，可以导致铁磁性的哈伯德模型包含不同的现场能量的三角形。它是基于一个有效的哈密顿量，我们推导出在强耦合极限。考虑到一维实现的模型，我们表明，在四分之一填充，绝缘的情况下，基态实际上是铁磁的在一个非常大的参数范围内从田崎{close_quote}的平带极限的强耦合极限的有效哈密顿量。这一结果已获得使用各种分析和数值技术。最后，同样的结果被证明适用于远离四分之一填充，在金属的情况下。美国物理学会（American Physical Society）
We propose a mechanism which can lead to ferromagnetism in Hubbard models containing triangles with different on-site energies. It is based on an effective Hamiltonian that we derive in the strong coupling limit. Considering a one-dimensional realization of the model, we show that in the quarter-filled, insulating case the ground state is actually ferromagnetic in a very large parameter range going from Tasaki{close_quote}s flatband limit to the strong coupling limit of the effective Hamiltonian. This result has been obtained using a variety of analytical and numerical techniques. Finally, the same results are shown to apply away from quarter-filling, in the metallic case. {copyright} {ital 1996 The American Physical Society.}