The influence of spin-flip scattering on the stability of ferromagnetism in a two-band Hubbard model

We investigate the influence of an interband exchange interaction on magnetism in a two-band Hubbard model. Our main emphasis lies on spin-flip scattering which is often neglected but is necessary to retain the full rotational symmetry of the Hamiltonian. We find a striking dependence of the magnetization on the interband exchange coupling constant J and a substantial suppression of ferromagnetic order for a large range of values of J. The onset of a Ruderman-Kittel-Kasuya-Yosida-like (RKKY-like) magnetic ordering mechanism is also observed.