STABILITY OF FERROMAGNETISM IN THE HUBBARD-MODEL

被引：77

作者：

TASAKI, H

机构：

[1] Department of Physics, Gakushuin University, Mejiro, Toshima-ku

来源：

PHYSICAL REVIEW LETTERS | 1994年 / 73卷 / 08期

关键词：

D O I：

10.1103/PhysRevLett.73.1158

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Recently certain Hubbard models with flat lowest bands were proved to exhibit ferromagnetism. Here we study perturbed models with nearly flat bands. We prove that the ferromagnetic state is stable against a single-spin flip for sufficiently large Coulomb interaction U, but is unstable for small U > 0. This is the first time that the (local) stability of ferromagnetism is proved in nonsingular Hubbard models, in which we must overcome competition between the kinetic energy and the Coulomb interaction,

引用

页码：1158 / 1161

页数：4

共 15 条

[1]

Herring C., 1966, MAGNETISM, V4

[2] ROBUSTNESS OF THE FERROMAGNETISM IN FLAT BANDS [J].