TY - JOUR
T1 - The role of spin-exchange on transport in quantum dots
AU - Wan, Yi
AU - Phillips, Philip
AU - Li, Qiming
N1 - Funding Information:
We thank Patrick Lee, Ylgal Meir, and RobertW est-ervelt for insightfulr emarks This work is supported in part by the NSF and the donors of the Petroleum Research Fund of the American Chemical Society, and the Director of Energy Research,O ffice of Basic Eerngy Sciences Ames Laboratoryis operatedfo r the U S DOE by Iowa State University under Contract No W-7405-ENG 82 While this work was in preparationa, paper appeared( L Wang, J K Zhang, and AR Bishop, Phys Rev Lett 73 (1994) 585) which reportedn umericacl alculationosn an extensive molecularo rbitalmodel for a quantumd ot Even-odd asymmetryw as predictedin the overall conductance However,t he weak peaks in the vicinity of the central coductancep eakswere not predicted
PY - 1995/5/15
Y1 - 1995/5/15
N2 - 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 (Jd) that is inherently present among the electrons occupying the various quantum levels of the dot. A Schrieffer-Wolff-type transformation is developed to analyze this model. We show explicitly that for ferromagnetic coupling (Jd > 0), an s-d exchange for an S = 1 Kondo problem is recovered. In contrast, for the antiferromagnetic case, Jd > 0, we find that the Kondo effect is present only if there are an odd number of electrons on the dot. Spin-exchange is then shown to produce a second period in the conductance that is consistent with experimental measurements.
AB - 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 (Jd) that is inherently present among the electrons occupying the various quantum levels of the dot. A Schrieffer-Wolff-type transformation is developed to analyze this model. We show explicitly that for ferromagnetic coupling (Jd > 0), an s-d exchange for an S = 1 Kondo problem is recovered. In contrast, for the antiferromagnetic case, Jd > 0, we find that the Kondo effect is present only if there are an odd number of electrons on the dot. Spin-exchange is then shown to produce a second period in the conductance that is consistent with experimental measurements.
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U2 - 10.1016/0167-2789(94)00264-Q
DO - 10.1016/0167-2789(94)00264-Q
M3 - Article
AN - SCOPUS:58149211956
SN - 0167-2789
VL - 83
SP - 280
EP - 285
JO - Physica D: Nonlinear Phenomena
JF - Physica D: Nonlinear Phenomena
IS - 1-3
ER -