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Kondo effect and spin filtering in triangular artificial atoms

Gergely Zarand·Arne Brataas·David Goldhaber-Gordon
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Abstract

We study strongly correlated states in triangular artificial atoms. Symmetry-driven orbital degeneracy of the single particle states can give rise to an SU(4) Kondo state with entangled orbital and spin degrees of freedom, and a characteristic phase shift $δ= π/4$. Upon application of a Zeeman field, a purely orbital Kondo state is formed with somewhat smaller Kondo temperature and a fully polarized current through the device. The Kondo temperatures are in the measurable range. The triangular atom also provides a tool to systematically study the singlet-triplet transitions observed in recent experiments.

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Gergely Zarand, Arne Brataas, David Goldhaber-Gordon. 2003-02-24. Kondo effect and spin filtering in triangular artificial atoms. https://doi.org/10.1016/s0038-1098(03)00180-7

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