| Affiliation: | (1) Department of Mathematics, Imperial College, SW7 2BZ London, UK;(2) Department of Material Science, Osaka City University, 558-8585 Sumiyoshi-ku, Osaka, Japan |
| Abstract: | We show that the low energy behaviour of quite diverse impurity systems can be described by a single renormalized Anderson model, with three parameters, an effective level  , an effective hybridization  , and a quasiparticle interaction  . The renormalized parameters are calculated as a function of the bare parameters for a number of impurity models, including those with coupling to phonons and a Falikov-Kimball interaction term. In the model with a coupling to phonons we determine where the interaction of the quasiparticles changes sign as a function of the electron-phonon coupling. In the model with a Falikov-Kimball interaction we show that to a good approximation the low energy behaviour corresponds to that of a bare Anderson model with a shifted impurity level.Received: 2 July 2004, Published online: 12 August 2004PACS: 75.20.Hr Local moment in compounds and alloys; Kondo effect, valence fluctuations, heavy fermions - 71.10.-w Theories and models of many-electron systems - 71.27. + a Strongly correlated electron systems; heavy fermions |
