Phase Transition of Ferromagnetic Fermi Liquid

Abstract

Critical phenomena of itinerant electron ferromagnets are investigated theoretically at T > Tc on the basis of a simple model in which the electron Coulomb repulsion is assumed to be effective only in an atomic cell. The ladder approximation or RPA used in our previous papers is now improved by taking into account the anomalous broadening of single-particle energy spectrum due to the scattering of individual particle motion by the critical spin fluctuations. The conservation law for the local magnetization is satisfied by the present treatment. The final results for the wavenumber dependent susceptibility and for the mass-operator of one-particle Green's function are expressed in compact forms. χ(q, 0) for small values of q is examined.