Theory of ferromagnetic semiconductors

!Based upon ab initio electronic structure calculations by the Korringa-Kohn-Rostoker coherent-potential approximation (KKR-CPA) method within the local-density approximation (LDA), we propose a unified physical picture of magnetism and an accurate calculation method of Curie temperature (T-C) in dilute magnetic semiconductors (DMSs) in II-VI and III-V compound semiconductors. We also propose the unified physical picture of magnetism in the DMS, where ferromagnetic Zener's double-exchange mechanism (or Zener's p-d exchange mechanism) caused by the partially occupied impurity band and anti-ferromagnetic super-exchange mechanism (or ferromagnetic super-exchange mechanism) is competing to determine the magnetic states in the DMS. We propose that the three-dimensional 3D Dairiseki-phase and one-dimensional ID Konbu-phase caused by spinodal nano-decomposition are responsible for high-T-C phase in the inhomogeneous system. We propose the new methodology to go beyond LDA to describe the highly correlated electron system by taking into account the self-interaction correction (SIC) to the LDA.