Suppression of the Kondo Effect in Quantum Dots by Even-Odd Asymmetry

Abstract

We analyze here a model for single-electron charging in semiconductor quantum dots that includes the standard Anderson on-site repulsion (U) as well as the spin-exchange ($J_d$) that is inherently present among the electrons occupying the various quantum levels of the dot. We show explicitly that for ferromagnetic coupling ($J_d>0$), an s-d exchange for an S=1 Kondo problem is recovered. In contrast, for the antiferromagnetic case, $J_d<0$, we find that the Kondo effect is present only if there are an odd number of electrons on the dot. In addition, we find that spin-exchange produces a second period in the conductance that is consistent with experimental measurements.

11 pages, RevTex, two postscript figures available

References in corpus (1)

• Low Temperature Transport through a Quantum Dot: The Anderson Model out of Equilibrium

Cited by in corpus (6)

• Kondo Physics in a Single Electron Transistor
• A Tunable Kondo Effect in Quantum Dots
• Kondo effect in an integer-spin quantum dot
• Kondo screening in Co adatoms with full Coulomb interaction
• Kondo effect in electrostatically defined ZnO quantum dots
• Kondo Effect in Mesoscopic Quantum Dots