Coqblin-Schrieffer Impurity with Local Exchange Coupling: a Perturbative Approach |
| P. Stefański Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Poznań, Poland |
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| The Coqblin-Schrieffer one-impurity model with the additional local exchange interaction is studied within diagrammatic approach. The Ruderman-Kittel-Kasuya-Yoshida-type local exchange interaction between f electrons of the impurity and a channel of conduction electron l=0 partial waves is treated in the molecular field approximation. The perturbation expansion resummation for the Coqblin-Schrieffer hybridization mediated interaction vertex part is carried out in the ladder approximation yielding the formula for the Kondo temperature TK decreasing with increased local exchange. Moreover, the temperature divergence of the susceptibility at TK is shifted towards T=0. For some critical strength of the local exchange interaction the susceptibility approaches a Curie-type dependence as for an uncompensated impurity magnetic moment. A relation to the "Kondo disorder" model, which leads to the non-Fermi-liquid behavior, is discussed. |
| DOI: 10.12693/APhysPolA.97.385 PACS numbers: 71.10.Hf, 71.20.Eh, 72.15.Qm, 75.20.Hr |