Quantum effects in double-exchange systems

被引：8

作者：

Brunton, RE ^{[1
]}

Edwards, DM ^{[1
]}

机构：

[1] Univ London Imperial Coll Sci Technol & Med, Dept Math, London SW7 2BZ, England

来源：

JOURNAL OF PHYSICS-CONDENSED MATTER | 1998年 / 10卷 / 24期

关键词：

D O I：

10.1088/0953-8984/10/24/018

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

The stability of ferromagnetism in the s-d model of double exchange is investigated variationally for quantum spins. It is shown rigorously that for S = 1/2 and infinite Hund's rule coupling, the state of complete spin alignment is unstable for 0.12 < n < 0.45, where n is the number of electrons per atom in the conduction band. Band narrowing in the paramagnetic state is also investigated in the quantum spin model. The effect is found to be somewhat stronger than in the classical spin limit and depends on n.

引用

页码：5421 / 5431

页数：11