ABSTRACT
Manipulating the magnetization direction of a magnetic layer with-out the use of an external magnetic field represents an outstanding opportunity and a challenge for spintronic applications. This chapter provides a coherent theoretical description of the topic for various phenomena involving the interplay between spin transport and magnetization dynamics. The spin transport in heterogeneous magnetic structures with a collinear magnetization configuration gives rise to a longitudinal spin density. In magnetic tunnel junctions, the spacer layer that separates the two ferromagnetic layers is a thin insulator in contrast with the metallic spacer in spin valves. The inelastic scattering of tunneling electrons by phonons or magnons is known to be detrimental to the tunneling magnetoresistance in magnetic tunnel junctions. Spin transport becomes even more intriguing in two- and three-dimensional textures such as vortices and skyrmions. Investigating the stability diagrams out of the stability regions reveals a rich variety of magnetization regimes, including in-plane precessions, out-of-plane precessions, and inhomogeneous magnetic excitations.
