Suppression of the Kondo effect in quantum dots by even-odd asymmetry
- Loomis Laboratory of Physics, University of Illinois at Urbana-Champaign, 1100 W. Green Street, Urbana, Illinois 61801-3080 (United States)
- Ames Laboratory and Department of Physics, Iowa State University, Ames, Iowa 50011 (United States)
We analyze here a model for single-electron charging in semiconductor quantum dots that includes the standard Anderson on-site repulsion ({ital U}) as well as the spin exchange ({ital J}{sub {ital d}}) that is inherently present among the electrons occupying the various quantum levels of the dot. We show explicitly that for ferromagnetic coupling ({ital J}{sub {ital d}}{gt}0), an {ital s}-{ital d} exchange for an {ital S}=1 Kondo problem is recovered. In contrast, for the antiferromagnetic case, {ital J}{sub {ital d}}{lt}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 as well as additional fine structure in the conductance that is consistent with experimental measurements.
- Research Organization:
- Ames National Laboratory
- DOE Contract Number:
- W-7405-ENG-82
- OSTI ID:
- 74032
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 51, Issue 20; Other Information: PBD: 15 May 1995
- Country of Publication:
- United States
- Language:
- English
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