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Structure and transport in multi-orbital Kondo systems

J. Kroha·S. Kirchner·G. Sellier·P. W"olfle·D. Ehm·F. Reinert·S. H"ufner·C. Geibel
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Abstract

We consider Kondo impurity systems with multiple local orbitals, such as rare earth ions in a metallic host or multi--level quantum dots coupled to metallic leads. It is shown that the multiplet structure of the local orbitals leads to multiple Kondo peaks above the Fermi energy $E_F$, and to ``shadow'' peaks below $E_F$. We use a slave boson mean field theory, which recovers the strong coupling Fermi liquid fixed point, to calculate the Kondo peak positions, widths, and heights analytically at T=0, and NCA calculations to fit the temperature dependence of high--resolution photoemission spectra of Ce compounds. In addition, an approximate conductance quantization for transport through multi--level quantum dots or single--atom transistors in the Kondo regime due to a generalized Friedel sum rule is demonstrated.

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J. Kroha, S. Kirchner, G. Sellier, P. W"olfle, D. Ehm, F. Reinert, S. H"ufner, C. Geibel. 2007-02-25. Structure and transport in multi-orbital Kondo systems. https://doi.org/10.1016/s1386-9477(02)00977-3

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