First-principles theory of dilute semiconductors

This review summarizes recent first-principles investigations of the electronic structure and magnetism of dilute magnetic semiconductors (DMSs) use in spintronics. Details of the electronic structure of transition-metal-doped III-V and II-VI semiconductors are described, especially how the electronic structure couples to the magnetic properties of an impurity. In addition, the underlying mechanism of the ferromagnetism in DMSs is investigated from the electronic structure point of view in order to establish a unified picture that explains the chemical trend of the magnetism in DMSs. A hybrid method (ab initio electronic-structure calculations coupled to Monte Carlo simulations for the thermal properties) is discussed for calculating the Curie temperature of DMSs. Finally, first-principles theory of transport properties of DMSs is reviewed. The contribution from FZÚ is mainly in the construction of effective disordered spin models and in the calculation of transport properties.

Schematic illustrating the MRAM device. Each magnetic pillar consists of three layers; two magnetic layers (depending on the magnetization direction of these layers) are separated by a nonmagnetic layer, yielding a structure with a regular GMR functionality. The binary code is stored as the coupling between the two magnetic layers in a pillar and it is read via the magnetoresistive property of the pillar.

¹Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
²Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
³Institute of Physics, Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-18221 Prague 8, Czech Republic
⁴Institut für Festkörperforschung, Forschungszentrum Jülich, D-52425 Jülich, Germany
⁵Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
⁶Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, CZ-61662 Brno, Czech Republic
⁷Department of Physics and Astronomy, Uppsala University, P.O. Box 516, SE-751 20 Uppsala, Sweden
⁸Institut Néel, MCBT, CNRS, 25 Avenue des Martyrs, BP 166, 38042 Grenoble Cedex 9, France
⁹Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
¹⁰Computational Materials Science Center, National Institute of Material Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan
¹¹CNR/INFM, Department of Physics, University of L’Aquila, Stanza A1/43, Via Vetoio 10, Coppito, L’Aquila, 67010 Abruzzo, Italy
¹²Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
¹³Institut für Festkörperforschung, Forschungszentrum Jülich, D-52425 Jülich, Germany