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NRG study of the Kondo effect in the presence of itinerant-electron ferromagnetism

J. Martinek·M. Sindel·L. Borda·J. Barnaś·J. König·G. Schön·J. von Delft
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Abstract

The Kondo effect in quantum dots (QDs) - artificial magnetic impurities - attached to ferromagnetic leads is studied with the numerical renormalization group (NRG) method. It is shown that the QD level is spin-split due to presence of ferromagnetic electrodes, leading to a suppression of the Kondo effect. We find that the Kondo effect can be restored by compensating this splitting with a magnetic field. Although the resulting Kondo resonance then has an unusual spin asymmetry with a reduced Kondo temperature, the ground state is still a locally-screened state, describable by Fermi liquid theory and a generalized Friedel sum rule, and transport in the unitary limit is not spin dependent.

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J. Martinek, M. Sindel, L. Borda, J. Barnaś, J. König, G. Schön, J. von Delft. 2004-01-29. NRG study of the Kondo effect in the presence of itinerant-electron ferromagnetism. https://doi.org/10.1103/physrevlett.91.247202

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