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.