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Probing many body effects in semicon...

Harvard University.

Probing many body effects in semiconductor nanostructures.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Probing many body effects in semiconductor nanostructures.
Author:	Potok, Ron M.
Description:	165 p.
Notes:	Advisers: Charles M. Marcus; David Goldhaber-Gordon.
Notes:	Source: Dissertation Abstracts International, Volume: 67-02, Section: B, page: 0950.
Contained By:	Dissertation Abstracts International67-02B.
Subject:	Physics, Condensed Matter.
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3205943
ISBN:	9780542549465

Probing many body effects in semiconductor nanostructures.
Potok, Ron M.

Probing many body effects in semiconductor nanostructures. - 165 p.

Advisers: Charles M. Marcus; David Goldhaber-Gordon.

Thesis (Ph.D.)--Harvard University, 2006.

A transverse electron focusing geometry is used to couple current from an emitter (either a quantum point contact or quantum dot) into a collector point contact. In a magnetic field, the collector point contact can be biased to transmit only a single spin, which allows a direct measure of spin polarization of the current incident on it. Spin polarization of >70% is found for a quantum point contact, while the spin of emitted current in the Coulomb blockade regime of a quantum dot is found to be polarized along the direction of the applied magnetic field regardless of the ground state spin transition.

ISBN: 9780542549465Subjects--Topical Terms:

226939
Physics, Condensed Matter.

Probing many body effects in semiconductor nanostructures.
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100 0 $a Potok, Ron M. $3 264043
245 1 0 $a Probing many body effects in semiconductor nanostructures.
300 $a 165 p.
500 $a Advisers: Charles M. Marcus; David Goldhaber-Gordon.
500 $a Source: Dissertation Abstracts International, Volume: 67-02, Section: B, page: 0950.
502 $a Thesis (Ph.D.)--Harvard University, 2006.
520 # $a A transverse electron focusing geometry is used to couple current from an emitter (either a quantum point contact or quantum dot) into a collector point contact. In a magnetic field, the collector point contact can be biased to transmit only a single spin, which allows a direct measure of spin polarization of the current incident on it. Spin polarization of >70% is found for a quantum point contact, while the spin of emitted current in the Coulomb blockade regime of a quantum dot is found to be polarized along the direction of the applied magnetic field regardless of the ground state spin transition.
520 # $a In the second set of experiments, we realize a highly correlated electron system, the two channel Kondo system, in a specific geometry of coupled quantum dots. The two channel Kondo model, in which a local magnetic moment is screened by two independent conduction reservoirs, is created in a double quantum dot system based on a proposal by Oreg and Goldhaber-Gordon [1]. Using electrostatic gates we demonstrate in situ control of the parameters of the two channel Kondo model. We tune continuously between two distinct Fermi-liquid regimes, which are characterized by different values of conductance through the nanostructure. We investigate the properties of this quantum phase transition and the associated two channel Kondo quantum critical point.
520 # $a This thesis describes two sets of experiments performed in quantum dots and quantum point contacts fabricated in GaAs/AlGaAs 2D electron gases. First, we investigate the role of interactions in determining the ground state of a quantum dot. Transport spectroscopy reveals both spin-increasing and spin-decreasing transitions, as well as higher-spin ground states. We then compare ground and excited state transport spectroscopy to direct measurements of the spin polarization of emitted current by developing the first mesoscopic spin polarizer/analyzer system using spin-selective transverse electron focusing.
520 # $a [1]Y. Oreg and D. Goldhaber-Gordon, Physical Review Letters 90, 133602 (2003).
590 $a School code: 0084.
650 # 0 $a Physics, Condensed Matter. $3 226939
690 $a 0611
710 0 # $a Harvard University. $3 212445
773 0 # $g 67-02B. $t Dissertation Abstracts International
790 $a 0084
790 1 0 $a Goldhaber-Gordon, David, $e advisor
790 1 0 $a Marcus, Charles M., $e advisor
791 $a Ph.D.
792 $a 2006
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