Coqblin-Schrieffer versus local exchange coupling: a perturbative renormalization group study.

Pavarini E., Andreani L. C.

Max Planck Inst Festkorperforsch Heisenbergstr 1 D-70569 Stuttgart Germany
Univ Pavia Dipartimento Fis A Volta Infm I-27100 Pavia Italy

As a model for the competition between local exchange (LE) and hybridization in rare earth systems we study a Hamiltonian given by the Coqblin-Schrieffer (CS) interaction, plus the exchange interaction derived from LE. The last term breaks the SU(N) symmetry of the CS model. By using the perturbative renormalization group, we show that the ground state of the model is the compensated CS ground state even in the presence of a relatively large LE coupling. However, when LE is stronger than a critical value, the system falls into an undercompensated Kondo ground state.
© Copyright 1999 Elsevier Science B.V. All rights reserved.

Physica B, 259-261 198-199, 1999.

Max-Planck Institut für Festkörperforschung;
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