Abstract:
In this talk I will present an overview of the magnetic properties in diluted III-V magnetic semiconductors and especially in GaMnAs. I will discuss in details the effects of the magnetic impurity concentration and the role of the compensation defects. I will also discuss the relation between ab-initio based studies and model calculations based on the non-perturbative V-Jpd model and address the problems and inconsistencies found in the literature. I will present recent calculations of the magnetic excitation spectrum which can be directly accessible with help of inelastic neutron scattering experiments.