کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1815430 | 1525244 | 2009 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Inter-impurity and impurity-host magnetic correlations in semiconductors with low-density transition-metal impurities
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Experiments on (Ga,Mn)As in the low-doping insulating phase have shown evidence for the presence of an impurity band at 110Â meV above the valence band. The motivation of this paper is to investigate the role of the impurity band in determining the magnetic correlations in the low-doping regime of the dilute magnetic semiconductors. For this purpose, we present results on the Haldane-Anderson model of transition-metal impurities in a semiconductor host, which were obtained by using the Hirsch-Fye quantum Monte Carlo (QMC) algorithm. In particular, we present results on the impurity-impurity and impurity-host magnetic correlations in two- and three-dimensional semiconductors with quadratic band dispersions. In addition, we use the tight-binding approximation with experimentally determined parameters to obtain the host band structure and the impurity-host hybridization for Mn impurities in GaAs. When the chemical potential is located between the top of the valence band and the impurity bound state (IBS), the impurities exhibit ferromagnetic (FM) correlations with the longest range. We show that these FM correlations are generated by the antiferromagnetic coupling of the host electronic spins to the impurity magnetic moment. Finally, we obtain an IBS energy of 100Â meV, which is consistent with the experimental value of 110Â meV, by combining the QMC technique with the tight-binding approach for an Mn impurity in GaAs.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica B: Condensed Matter - Volume 404, Issues 8â11, 1 May 2009, Pages 1159-1168
Journal: Physica B: Condensed Matter - Volume 404, Issues 8â11, 1 May 2009, Pages 1159-1168
نویسندگان
Yoshihiro Tomoda, Nejat Bulut, Sadamichi Maekawa,