Phase diagram of a model for diluted magnetic semiconductors beyond mean-field approximations

被引:77
作者
Alvarez, G [1 ]
Mayr, M
Dagotto, E
机构
[1] Florida State Univ, Natl High Magnet Field Lab, Tallahassee, FL 32310 USA
[2] Florida State Univ, Dept Phys, Tallahassee, FL 32310 USA
[3] Max Planck Inst Festkorperforsch, D-70569 Stuttgart, Germany
基金
美国国家科学基金会;
关键词
D O I
10.1103/PhysRevLett.89.277202
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
A lattice spin-fermion model for diluted magnetic semiconductors (DMS) is investigated numerically, improving on previously used mean-field approximations. Curie temperatures are obtained varying the Mn spin x and hole n densities, and the impurity-hole exchange J in units of the hopping t. Optimal values are found in the subtle intermediate regime between itinerant and localized carriers. At intermediate and large J/t, a "clustered" state is observed above the Curie temperature and ferromagnetism is suppressed. Formal analogies between DMS and manganites are discussed.
引用
收藏
页码:277202 / 277202
页数:4
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