Spin-orbit induced properties of magnetic solids

Spin-orbit coupling gives rise in magnetic solids to a large number of effects that are at the same time of great scientific as well as technological interest. In fact they often play a central role in modern spintronics concepts and devices. As examples for this, results of investigations based on a fully relativistic Dirac formalism on the magneto-crystalline anisotropy, transport properties and the Gilbert damping parameter will be presented. As it will be demonstrated, a coherent treatment of the magnetic anisotropy can be achieved by including the Breit interaction that gives rise to the so-called dipolar shape anisotropy. Kubo's linear response formalism provides a sound and powerful basis for investigations on transport properties including any type of spin-orbit induced phenomenon. As corresponding examples results of ab-initio studies on the anomalous Hall effect in ferromagnets and on the spin transport in non-magnetic alloys will be presented. A central quantity when dealing with the magnetization dynamics in magnetic materials is the Gilbert damping parameter. An expression for this could also be given based on the linear response formalism that allows parameter-free calculations as will be demonstrated by corresponding results for various types of alloys. The numerical results presented will be accompanied by corresponding group theoretical symmetry considerations. These show in particular that - in agreement with numerical results - non-collinear magnetism is an important additional possible source for the physical phenomena discussed.