Physics of Complex Magnetic Materials: Quasiparticle Many-Body Dynamics

Abstract

A brief survey of the author's works on the quantum theory of magnetism. Theoretical foundation and applications of the generalized spin-fermion (sp-d) exchange lattice model to various magnetic systems, e.g., rare-earth metals and compounds, and magnetic and diluted magnetic semiconductors are discussed briefly. The main emphasis is put on the dynamic behavior of two interacting subsystems, the localized spins and spin density of itinerant carriers. A nonperturbative many-body approach was used to describe the quasiparticle dynamics. The approach permits to investigate and clarify the role of various interactions and disorder effects in combined quantum models of magnetism in unified and coherent fashion.