Spin dynamics in magnetic nanostructures

Coherent magnetization dynamics in ferromagnetic metals "drags" quasiparticle spins resulting in a source of magnetic dissipation and noise on the one hand and quasiparticle spin flows on the other. The consequences can be especially dramatic in heterostructures where interfaces result in dynamic leakage of the magnetic order parameter, as confirmed in a number of recent experiments. Developing these ideas allows to lay ground for a general treatment of the semiclassical interaction between order-parameter dynamics and quasiparticle flows in heterostructures and bulk. As a demonstration of general principles, I will first discuss curious examples of interplay between helical, magnetic, and superconducting ordering in time-dependent problems. Finally, I will talk about the interaction of charge currents and magnetization dynamics in itinerant ferromagnets with some surprising results.