Magnetic excitations in iron pnictides

Spin wave dispersion and damping are investigated in the metallic SDW state of different itinerant electron models including a small interlayer hopping. Magnetic excitations in iron pnictides are shown to be well understood in terms of physical mechanisms characteristic of metallic magnets, such as carrier-induced ferromagnetic spin couplings, intra-band particle-hole excitations, and the spin-charge coupling mechanism, which is also important in ferromagnetic manganites.