New Spin-Wave Mode in Weak Ferromagnetic Fermi Liquids

We study a phenomenological model for weak ferromagnetic Fermi liquids and investigate the properties of the spin waves in the model. The Landau kinetic equation is used to derive, in addition to the known Goldstone mode, a new spin-wave mode – the first Silin-like ferromagnetic mode. We discuss the role of the interaction parameter F^a_1 on the behavior of the Goldstone mode and the first Silin-like ferromagnetic mode.