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Spin effects in single-electron transistors

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2005. / Includes bibliographical references (p. 169-175). / Basic electron transport phenomena observed in single-electron transistors (SETs) are introduced, such as Coulomb-blockade diamonds, inelastic cotunneling thresholds, the spin-1/2 Kondo effect, and Fano interference. With a magnetic field parallel to the motion of the electrons, single-particle energy levels undergo Zeeman splitting according to their spin. The g-factor describing this splitting is extracted in the spin-flip inelastic cotunneling regime. The Kondo splitting is linear and slightly greater than the Zeeman splitting. At zero magnetic field, the spin triplet excited state energy and its dependence on gate voltage are measured via sharp Kondo peaks superimposed on inelastic cotunneling thresholds. Singlet-triplet transitions and an avoided crossing are analyzed with a simple two-level model, which provides information about the exchange energy and the orbital mixing. With four electrons on the quantum dot, the spin triplet state has two characteristic energy scales, consistent with a two-stage Kondo effect description. The low energy scale extracted from a nonequilibrium measurement is larger than those extracted in equilibrium. / by Ghislain Granger. / Ph.D.

Identiferoai:union.ndltd.org:MIT/oai:dspace.mit.edu:1721.1/32305
Date January 2005
CreatorsGranger, Ghislain
ContributorsMarc A. Kastner., Massachusetts Institute of Technology. Dept. of Physics., Massachusetts Institute of Technology. Dept. of Physics.
PublisherMassachusetts Institute of Technology
Source SetsM.I.T. Theses and Dissertation
LanguageEnglish
Detected LanguageEnglish
TypeThesis
Format175 p., application/pdf
RightsM.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission., http://dspace.mit.edu/handle/1721.1/32305, http://dspace.mit.edu/handle/1721.1/7582

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