Ferromagnetism in a Hubbard model for an atomic quantum wire: A realization of flat-band magnetism from even-membered rings

被引：29

作者：

Arita, R ^{[1
]}

Kuroki, K

Aoki, H

Yajima, A

Tsukada, M

Watanabe, S

Ichimura, M

Onogi, T

Hashizume, T

机构：

[1] Univ Tokyo, Dept Phys, Tokyo 113, Japan

[2] Univ Tokyo, Dept Mat Sci, Tokyo 113, Japan

[3] Hitachi Ltd, Adv Res Lab, Hatoyama, Saitama 35003, Japan

来源：

PHYSICAL REVIEW B | 1998年 / 57卷 / 12期

关键词：

D O I：

10.1103/PhysRevB.57.R6854

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We have examined as a Hubbard model on a chain of squares, which was as proposed by Yajima et al. as a model of an atomic quantum wire As/Si(100), to show that the flat-band ferromagnetism according to a kind of Mielke-Tasaki mechanism should be realized for an appropriate band filling in such a nonfrustrated lattice. Reflecting the fact that the flat band is not a bottom one, the ferromagnetism vanishes, rather than intensifies, as the Hubbard U is increased. The exact-diagonalization method is used to show that the critical value of U is in a realistic range. We also discussed the robustness of the magnetism against the degradation of the flatness of the band.

引用

页码：R6854 / R6857

页数：4

共 15 条

[1]

Hashizume T, 1996, JPN J APPL PHYS 2, V35, pL1085

[2] Aspects of the ground state of the U=∞ Hubbard ladder [J].