Spintronic transport and Kondo effect in quantum dots

D. Sánchez, R. López, M. S. Choi

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

We investigate the spin-dependent transport properties of quantum-dot based structures where Kondo correlations dominate the electronic dynamics. The coupling to ferromagnetic leads with parallel magnetizations is known to give rise to nontrivial effects in the local density of states of a single quantum dot. We show that this influence strongly depends on whether charge fluctuations are present or absent in the dot. This result is confirmed with numerical renormalization group calculations and perturbation theory in the on-site interaction. In the Fermi-liquid fixed point, we determine the correlations of the electric current at zero temperature (shot noise) and demonstrate that the Fano factor is suppressed below the Poissonian limit for the symmetric point of the Anderson Hamiltonian even for nonzero lead magnetizations. We discuss possible avenues of future research in this field: coupling to the low energy excitations of the ferromagnets (magnons), extension to double quantum dot systems with interdot antiferromagnetic interaction and effect of spin-polarized currents on higher symmetry Kondo states such as SU(4).

Original languageEnglish
Pages (from-to)251-260
Number of pages10
JournalJournal of Superconductivity and Novel Magnetism
Volume18
Issue number2
DOIs
Publication statusPublished - 2005 Dec 1

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Keywords

  • Ferromagnet
  • Kondo effect
  • Quantum dot
  • Spintronics

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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