Local Quasiparticles in the Anderson Model

With a new spectral density approach it is shown firstly that the ground state of the Anderson model is nonmagnetic. Local quasiparticles corresponding to transitions between different occupancies of the impurity orbital are shown to be well defined and well separated for realistic values of the parameters of the Anderson model. Lifetimes of the quasiparticles strongly depend on the hybridization coupling constant Vdk and are almost independent of temperature. The maxima of the spectral density Adσ(ω) are in qualitative agreement with the results of the optical absorption experiments performed on noble metal alloys containing 3d magnetic impurities.