FERROMAGNETIC SPIN-WAVE THEORY IN THE MULTIBAND HUBBARD-MODEL HAVING A FLAT-BAND

被引：69

作者：

KUSAKABE, K

AOKI, H

机构：

[1] Department of Physics, University of Tokyo, Hongo

来源：

PHYSICAL REVIEW LETTERS | 1994年 / 72卷 / 01期

关键词：

D O I：

10.1103/PhysRevLett.72.144

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

The peculiar effect of electron correlation in multiband systems is illustrated for the recently proposed ferromagnetism in a Hubbard model having flat bands. Despite the flatness of the band, an acoustic spin-wave mode with a finite stiffness exists along with optical modes below a Stoner gap. The relevant energy (gap and stiffness) transmutes from the Hubbard U in the weak-coupling limit to t (transfer integral) in the strong-coupling limit. This implies a stable itinerant ferromagnetism with finite band widths.

引用

页码：144 / 147

页数：4

共 16 条

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