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MODELING NANODEVICES:
FROM SEMICONDUCTOR HETEROSTRUCTURES TO JOSEPHSON JUNCTION
ARRAYS
Copyright 2012
by
Bruna Pereira Wanderley de Oliveira
A Dissertation Presented to the
FACULTY OF THE USC GRADUATE SCHOOL
UNIVERSITY OF SOUTHERN CALIFORNIA
In Partial Fulfillment of the
Requirements for the Degree
DOCTOR OF PHILOSOPHY
(PHYSICS)
May 2012
Bruna Pereira Wanderley de Oliveira
Object Description
| Title | Modeling nanodevices: from semiconductor heterostructures to Josephson junction arrays |
| Author | de Oliveira, Bruna Pereira Wanderley |
| Author email | deolivei@usc.edu;bdeolive@gmail.com |
| Degree | Doctor of Philosophy |
| Document type | Dissertation |
| Degree program | Physics |
| School | College of Letters, Arts And Sciences |
| Date defended/completed | 2012-03-05 |
| Date submitted | 2012-04-30 |
| Date approved | 2012-05-01 |
| Restricted until | 2012-05-01 |
| Date published | 2012-05-01 |
| Advisor (committee chair) | Haas, Stephan |
| Advisor (committee member) |
Dappen, Werner Roscilde, Tommaso Bickers, Nelson El-Naggar, Mohamed Cronin, Stephen |
| Abstract | In this thesis we study the physical properties of two distinct physical systems. First, a generalized propagation matrix method is used to study how scattering off local Einstein phonons affects resonant electron transmission through quantum wells. In particular, the parity and the number of the phonon mediated satellite resonances are found to depend on the available scattering channels. For a large number of phonon channels, the formation of low-energy impurity bands is observed. Furthermore, an effective theory is developed which accurately describes the phonon generated sidebands for sufficiently small electron-phonon coupling. Finally, the current-voltage characteristics caused by phonon assisted transmission satellites are discussed for a specific double barrier geometry. In the second part of this thesis we numerically investigate the complex interplay between frustration and disorder in a magnetically frustrated Josephson junction array on the square lattice with site dilution, modeled by the fully frustrated classical XY model on the same lattice. This system has a superconducting ground state featuring a vortex crystal induced by frustration. In absence of dilution this system is known to exhibit two thermal transitions: a Kosterlitz- Thouless transition at which superconductivity and quasi-long-range phase order disappear, and a higher-temperature transition at which the vortex crystal melts - the two critical temperatures delimit a chiral phase. We find that dilution enhances the width of the chiral phase, and that at a critical dilution superconductivity is suppressed down to zero temperature, while chiral order survives - the corresponding ground state of the system becomes therefore a chiral phase glass. At an even higher dilution chiral order disappears in the ground state, leaving the system in a vortex and phase glass state. We reconstruct the complex phase diagram via extensive Monte Carlo simulations, and we investigate the main signatures of the various phases in the transport properties (I-V characteristics). |
| Keyword | Josephson junction arrays; electronic transport; phase transitions |
| Language | English |
| Part of collection | University of Southern California dissertations and theses |
| Publisher (of the original version) | University of Southern California |
| Place of publication (of the original version) | Los Angeles, California |
| Publisher (of the digital version) | University of Southern California. Libraries |
| Provenance | Electronically uploaded by the author |
| Type | texts |
| Legacy record ID | usctheses-m |
| Rights | de Oliveira, Bruna Pereira Wanderley |
| Access conditions | The author retains rights to his/her dissertation, thesis or other graduate work according to U.S. copyright law. Electronic access is being provided by the USC Libraries in agreement with the author, as the original true and official version of the work, but does not grant the reader permission to use the work if the desired use is covered by copyright. It is the author, as rights holder, who must provide use permission if such use is covered by copyright. The original signature page accompanying the original submission of the work to the USC Libraries is retained by the USC Libraries and a copy of it may be obtained by authorized requesters contacting the repository e-mail address given. |
| Repository name | University of Southern California Digital Library |
| Repository address | USC Digital Library, University of Southern California, University Park Campus MC 7002, 106 University Village, Los Angeles, California 90089-7002, USA |
| Repository email | cisadmin@usc.edu |
| Archival file | uscthesesreloadpub_Volume4/etd-deOliveira-685.pdf |
Description
| Title | Page 1 |
| Full text | MODELING NANODEVICES: FROM SEMICONDUCTOR HETEROSTRUCTURES TO JOSEPHSON JUNCTION ARRAYS Copyright 2012 by Bruna Pereira Wanderley de Oliveira A Dissertation Presented to the FACULTY OF THE USC GRADUATE SCHOOL UNIVERSITY OF SOUTHERN CALIFORNIA In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY (PHYSICS) May 2012 Bruna Pereira Wanderley de Oliveira |
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