Abstract
The local Cu-O model is a local version of the extended Hubbard model and corresponds to a two-channel Anderson impurity model in which the two channels correspond to screening and hybridizing channels, respectively, and the screening interaction, , is short range. The model represents a more realistic model for the local excitations in heavy fermions and may also be of relevance in understanding the normal state properties of high temperature superconductors. Below a critical screening strength, < the particle-hole symmetric model exhibits Fermi-liquid behavior, whereas for > a non-Fermi-liquid state forms. Here, we report results of a numerical renormalization group calculation for the spectral density of single-particle excitations, in both the Fermi-liquid and non-Fermi-liquid regimes. The Kondo resonance is strongly modified for close to and is destroyed for >. The relevance of these results for high temperature superconductors and the photoemission spectra of heavy fermions is discussed.
- Received 22 August 1996
DOI:https://doi.org/10.1103/PhysRevB.55.6670
©1997 American Physical Society