Ferromagnetism in the Hubbard models with degenerate single-electron ground states.
Ferromagnetism in the Hubbard models with degenerate single-electron ground states.
复制标题
DOI：
10.1103/physrevlett.69.1608
复制
发表时间：
1992-09
影响因子：
8.6
通讯作者：
H. Tasaki
中科院分区：
文献类型：
--
作者：
H. Tasaki
研究了一类单电子基态具有体简并性的Hubbard模型。我们证明了当电子填充因子不大于并充分接近ρ 0 = ρ 0时，模型的基态表现出铁磁性|V|/2| Λ|（此处|V|是简并的维度，|Λ|是位置的数量），并且当填充因子足够小时表现出顺磁性。这是第一次证明三维巡游电子系统在有限的电子填充因子范围内表现出铁磁性
We study a class of Hubbard models in which the corresponding single-electron ground states have bulk degeneracy. We prove that the ground states of the models exhibit ferromagnetism when the electron filling factor is not more than and sufficiently close to ρ 0 =|V|/2|Λ| (where |V| is the dimension of degeneracy and |Λ| is the number of sites), and exhibit paramagnetism when the filling factor is sufficiently small. This is the first time that a three-dimensional itinerant-electron system is proved to exhibit ferromagnetism in a finite range of the electron filling factor