Tags: Ph.D. thesis

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  1. Quantitative Modeling and Simulation of Quantum Dots

    18 Apr 2011 | | Contributor(s):: Muhammad Usman

    Quantum dots grown by self-assembly process are typically constructed by 50,000 to 5,000,000 structural atoms which confine a small, countable number of extra electrons or holes in a space that is comparable in size to the electron wavelength. Under such conditions quantum dots can be...

  2. Professor's and Student's Perceptions and Experiences of Computational Simulations as Learning Tools

    04 Apr 2010 | | Contributor(s):: Alejandra J. Magana

    Computational simulations are becoming a critical component of scientific and engineering research, and now are becoming an important component for learning. This dissertation provides findings from a multifaceted research study exploring the ways computational simulations have been perceived...

  3. Quantum transport in semiconductor nanostructures

    04 Mar 2010 | | Contributor(s):: Tillmann Christoph Kubis

    PhD thesis of Tillmann Christoph KubisThe main objective of this thesis is to theoretically predict the stationary charge and spin transport in mesoscopic semiconductor quantum devices in the presence of phonons and device imperfections. It is well known that the nonequilibrium Green's function...

  4. Role of Spin-Orbit Interaction and Berry's Phase in Aharonov-Bohm Oscillations

    04 Mar 2009 | | Contributor(s):: Jeng-Bang (Tony) Yau

    In this thesis we report the results of study on the role of spin-orbit (SO) interaction in Aharonov-Bohm (A-B) oscillations measured in (311)A GaAs two-dimensional (2D) holes, and the observed novel structures in the Fourier transform (FT) spectra of the A-B oscillations, which we interpret as...

  5. First Principles Non-Equilibrium Green's Function Modeling of Vacum and Oxide Barrier Tunneling

    01 Dec 2008 | | Contributor(s):: Kirk H. Bevan

    Vacuum and oxide barrier electron tunneling phenomena have been studied at length for several decades. Yet with electron device barrier widths now commonly measured in atomic units, complex quantum mechanical phenomena such as wavefunction coupling, surface states, and interface bonds have begun...

  6. Application of the Keldysh Formalism to Quantum Device Modeling and Analysis

    14 Jan 2008 | | Contributor(s):: Roger Lake

    The effect of inelastic scattering on quantum electron transport through layered semi-conductor structures is studied numerically using the approach based on the non-equilibrium Green's function formalism of Keldysh, Kadanoff, and Baym. The Markov assumption is not made, and the energy...

  7. Electron-Phonon and Electron-Electron Interactions in Quantum Transport

    14 Jan 2008 | | Contributor(s):: Gerhard Klimeck

    The objective of this work is to shed light on electron transport through sub-micron semi-conductor structures, where electronic state quantization, electron-electron interactions and electron-phonon interactions are important. We concentrate here on the most developed vertical quantum device,...

  8. Quantum Ballistic Transport in Semiconductor Heterostructures

    27 Aug 2007 | | Contributor(s):: Michael McLennan

    The development of epitaxial growth techniques has sparked a growing interest in an entirely quantum mechanical description of carrier transport. Fabrication methods, such as molecular beam epitaxy (MBE), allow for growth of ultra-thin layers of differing material compositions. Structures can be...

  9. Modeling Quantum Transport in Nanoscale Transistors

    30 Oct 2006 | | Contributor(s):: ramesh venugopal

    As critical transistor dimensions scale below the 100 nm (nanoscale) regime, quan- tum mechanical effects begin to manifest themselves and affect important device performance metrics. Therefore, simulation tools which can be applied to design nanoscale transistors in the future, require new...

  10. Carbon Nanotube Electronics: Modeling, Physics, and Applications

    30 Oct 2006 | | Contributor(s):: Jing Guo

    In recent years, significant progress in understanding the physics of carbon nanotube electronic devices and in identifying potential applications has occurred. In a nanotube, low bias transport can be nearly ballistic across distances of several hundred nanometers. Deposition of high-κ gate...

  11. Nanoscale MOSFETs: Physics, Simulation and Design

    26 Oct 2006 |

    This thesis discusses device physics, modeling and design issues of nanoscale transistors at the quantum level. The principle topics addressed in this report are 1) an implementation of appropriate physics and methodology in device modeling, 2) development of a new TCAD (technology computer...

  12. Device Physics and Simulation of Silicon Nanowire Transistors

    28 Sep 2006 |

    As the conventional silicon metal-oxide-semiconductor field-effect transistor (MOSFET) approaches its scaling limits, many novel device structures are being extensively explored. Among them, the silicon nanowire transistor (SNWT) has attracted broad attention from both the semiconductor industry...

  13. Nanoscale Device Modeling: From MOSFETs to Molecules

    20 Sep 2006 |

    This thesis presents a rigorous yet practical approach to model quantum transport in nanoscale electronic devices.As convetional metal oxide semiconductor devices shrink below the one hundred nanometer regime, quantum mechanical effects are beginning to play an increasingly important role in...

  14. Exploring New Channel Materials for Nanoscale CMOS

    21 May 2006 | | Contributor(s):: anisur rahman

    The improved transport properties of new channel materials, such as Ge and III-V semiconductors, along with new device designs, such as dual gate, tri gate or FinFETs, are expected to enhance the performance of nanoscale CMOS devices.Novel process techniques, such as ALD, high-k dielectrics, and...