Renormalization of spin excitations and Kondo effect in open-shell nanographenes

Renormalization Group Approaches to the Kondo Effect

Kodon effect was first introduced by Knondo in 1964 for explaining the extraordinary resistivity of metals with magnetic impurities: The resistivity ρ(T ) increases as temperature T goes to zero. This problem can be well understood by the method of the renormalization group. In this essay, the renormalization group is used to analyze the effective coupling of the impuity with the conduction ele...

Spin-orbit scattering and the Kondo effect.

The effects of spin-orbit scattering of conduction electrons in the Kondo regime are investigated theoretically. It is shown that due to time-reversal symmetry, spin-orbit scattering does not suppress the Kondo effect, even though it breaks spin-rotational symmetry, in full agreement with experiment. An orbital magnetic field, which breaks time-reversal symmetry, leads to an effective Zeeman sp...

Spin correlations and Kondo effect in a strong ferromagnet

Kondo effect and spin filtering in triangular artificial atoms

We studied, strongly correlated states in triangular artificial atoms. Symmetry-driven orbital degeneracy of the single particle states can give rise to an SUð4Þ Kondo state with entangled orbital and spin degrees of freedom, and a characteristic phase shift d 1⁄4 p=4: Upon application of a Zeeman field, a purely orbital Kondo state is formed with somewhat smaller Kondo temperature and a fully ...

Quantum renormalization of the spin Hall effect.

By quantum Monte Carlo simulation of a realistic multiorbital Anderson impurity model, we study the spin-orbit interaction (SOI) of an Fe impurity in Au host metal. We show, for the first time, that the SOI is strongly renormalized by the quantum spin fluctuation. Based on this mechanism, we can explain why the gigantic spin Hall effect in Au with Fe impurities was observed in recent experiment...