Formation of a heavy quasiparticle state in two-band Hubbard model
Formation of a heavy quasiparticle state in two-band Hubbard model
复制标题
双能带哈伯德模型中重准粒子态的形成
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
K. Miyake
中科院分区：
文献类型：
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作者：
H. Kusunose;S. Yotsuhashi;K. Miyake
在双带Hubbard模型的基础上研究了重费米子态的一种实现。在从玻色子平均场近似下，当电子密度ne = 1.5时，带间库仑排斥U强烈地强调了带间的初始小差异，并容易稳定下带的积分价.结果，在低带和两带之间的混合强度发生了强重整化。在准粒子态密度的费米能级上出现一个尖峰，与周期性安德森模型的结果相同。与洪德规则耦合J降低特征能量的简单见解相反，它与J < U的重整化几乎无关。所需的条件适合于LiV2O4，第一个观察到的重费米子化合物在过渡金属氧化物。
A realization of heavy fermion state is investigated on the basis of two-band Hubbard model. By means of the slave-boson mean-field approximation, it is shown that for the intermediate electron density, ne = 1.5, the inter-band Coulomb repulsion U strongly emphasizes initially small difference between bands, and easily stabilizes integral valence in the lower band. As a result, a strong renormalization takes place in the lower band and the mixing strength between two bands. It gives rise to a sharp peak at the Fermi level in the quasiparticle density of states, as that obtained in the periodic Anderson model. In contrast to a simple insight that the Hund’s-rule coupling J reduces the characteristic energy, it turns out to be almost irrelevant to the renormalization for J < U. The required conditions are suitable for LiV2O4, the first observed heavy fermion compound in transition metal oxide.