Abstract
We present high-resolution, angle-resolved photoemission spectra for Ce-based and U-based strongly correlated electron systems. The experimental results are irreconcilable with the long-accepted single-impurity model, which predicts a narrow singlet state, in close proximity to the Fermi energy, whose linewidth and binding energy are a constant determined by a characteristic temperature for the material. We report that both and photoemission features disperse with crystal momentum at temperatures both above and below these are characteristics consistent with narrow bands but not with the single-impurity model. Inclusion of the lattice must be considered at all temperatures. Variants of the periodic Anderson model are consistent with this approach.
- Received 6 March 1997
DOI:https://doi.org/10.1103/PhysRevB.56.R7041
©1997 American Physical Society