Theory of Spin Waves in Ferromagnetic Metals with Multiple Bands

摘要: Dispersion relations of spin waves in ferromagnetic metals with multiple bands are obtained by the method normal mode within random phase approximation and a certain for Coulomb interaction. It is found that wave spectra consist one acoustical branch, some optical branches other due to inter-band transitions. The transitions have an important effect on dispersion relation at larger momentum. coefficient square momentum be sum D B H which derived from intra-atomic inter-atomic exchange interactions, respectively. For nickel, value estimated as about 0.1 eVA 2 using model two overlapping bands, it concluded \(D_{B}{\lesssim}D_{H}\).