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Theories of imaging electrons in nan...

Harvard University.

Theories of imaging electrons in nanostructures.

Record Type:	Electronic resources : Monograph/item
Title/Author:	Theories of imaging electrons in nanostructures.
Author:	Huang, Jian.
Description:	174 p.
Notes:	Adviser: Eric J. Heller.
Notes:	Source: Dissertation Abstracts International, Volume: 67-05, Section: B, page: 2615.
Contained By:	Dissertation Abstracts International67-05B.
Subject:	Physics, Condensed Matter.
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3217766
ISBN:	9780542692833

Theories of imaging electrons in nanostructures.
Huang, Jian.

Theories of imaging electrons in nanostructures. - 174 p.

Adviser: Eric J. Heller.

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

Experiments on nanostructures have yielded a very rich body of data. Very often the experimental temperature is low enough to make S-wave scattering applicable, and the coherence length is significant enough such that phase factors play an important role. In this thesis, multiple scattering theory (MST) is applied to studying first an acoustic experiment and then 2-dimensional electron gases (2DEGs) in nanoscale systems; a finite difference method (FDM) is employed to solve the Schrodinger equation for a single-electron quantum dot with various boundary conditions; numerical techniques are developed to study cusps in 2DEGs and their tip scan images. In total, five closely related projects are described in this thesis.

ISBN: 9780542692833Subjects--Topical Terms:

226939
Physics, Condensed Matter.

Theories of imaging electrons in nanostructures.
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100 0 $a Huang, Jian. $3 243583
245 1 0 $a Theories of imaging electrons in nanostructures.
300 $a 174 p.
500 $a Adviser: Eric J. Heller.
500 $a Source: Dissertation Abstracts International, Volume: 67-05, Section: B, page: 2615.
502 $a Thesis (Ph.D.)--Harvard University, 2006.
520 # $a Experiments on nanostructures have yielded a very rich body of data. Very often the experimental temperature is low enough to make S-wave scattering applicable, and the coherence length is significant enough such that phase factors play an important role. In this thesis, multiple scattering theory (MST) is applied to studying first an acoustic experiment and then 2-dimensional electron gases (2DEGs) in nanoscale systems; a finite difference method (FDM) is employed to solve the Schrodinger equation for a single-electron quantum dot with various boundary conditions; numerical techniques are developed to study cusps in 2DEGs and their tip scan images. In total, five closely related projects are described in this thesis.
520 # $a In the fifth project, numerical techniques for generating classical and quantum cusps in 2DEGs are developed. Their tip scan images are analyzed to show interesting dynamics in imaging process. The classical folding of quantum cusp is demonstrated at short wavelength. More complicated, overlapping cusps are shown as well. Most importantly, experimental cusps are matched nicely by numerical results from the Kirchhoff method.
520 # $a In the first project, starting with the usual Lippman-Schwinger formulation of MST, a perturbative MST is developed to express in terms of the original field the changes induced by removing, adding, shifting, and changing a scatterer. The formalism is intuitive and easy to implement numerically.
520 # $a In the fourth project, first FDM is employed to solve for ground state energy of a single-electron quantum dot, which leads to its conductance peak patterns under tip scan. Singular value decomposition (SVD) is then utilized to invert matrix to extract electron wavefunction out of the experimental conductance data. The stability and sensitivity to boundary conditions of FDM and SVD are also studied.
520 # $a In the second project, time-reversal focusing in sound scattering is studied in terms of MST. Many important features of the experimental system are revealed for the first time. An interpretation is provided to explain some recent experimental observations.
520 # $a In the third project, MST is applied to 2DEGs in the S-wave scattering limit. Many novel conductance fringe patterns are revealed and a general formulation is given for these patterns. Also provided are estimation formulas of thermal width for the circular, elliptical, and hyperbolic fringes, which are found to be consistent with numerical results.
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 67-05B. $t Dissertation Abstracts International
790 $a 0084
790 1 0 $a Heller, Eric J., $e advisor
791 $a Ph.D.
792 $a 2006
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