Exciton effects in a scaling theory of intermediate valence and Kondo systems
V. Yu. Irkhin, M. I. Katsnelson+
Institute of Metal Physics, 620219 Ekaterinburg, Russia
+University of Nijmegen, NL 6525 ED Nijmegen, The Netherlands
PACS: 71.27.+a, 71.28.+d, 75.30.Mb
Abstract
An interplay of the Kondo scattering and exciton
effects (d-f Coulomb interaction) in the intermediate valence systems and
Kondo lattices is demonstrated to lead to an essential change of the scaling
behavior in comparison with the standard Anderson model. In particular, a
marginal regime can occur where characteristic fluctuation rate is
proportional to flow cutoff parameter. In this regime the "Kondo
temperature" itself is strongly temperature dependent which may give a key
to the interpretation of controversial experimental data for heavy fermions
and related systems.