Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Apr. 9, 2009). PDF text: v, 156 p. : ill. (some col.) ; 9 Mb. UMI publication number: AAT 3338831. Includes bibliographical references. Also available in microfilm and microfiche formats.

Thesis (M. Sc.)--University of Alberta, 2009. / Title from pdf file main screen (viewed on Sept 22, 2009). "A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Electrical and Computer Engineering, University of Alberta." Includes bibliographical references.

<p> The Langmuir-Blodgett deposition process is investigated for creating polystyrene nanosphere monolayers on a hydrophilic silicon substrate. The monolayers are fabricated over areas ~1 cm² and sputter coated with 100&Aring; of permalloy. The quality of the monolayers is analyzed with optical microscope image processing, and 2D Fourier transforms of electron microscope images. The magnetic switching behavior of the sputtered samples is measured using an alternating gradient magnetometer, and compared to completely flat permalloy. The magnetic hysteresis measurements are done at different angle between the easy and hard axis of the flat permalloy films. The measurements show different hysteresis shapes for nanosphere patterned permalloy and flat permalloy, with the difference becoming greater nearer the hard axis of the flat permalloy samples. The ambiguity of an easy or hard axis on a curved surface is likely to contribute to the difference in magnetic switching behavior between the two sample types.</p><p>

<p> Thin films of chlorine (Cl) and copper (Cu) doped zinc selenide (Cl:ZnSe and Cu:ZnSe) were fabricated by pulsed laser deposition (PLD) with the goal of enabling a multilayered semiconductor structure for a mid-infrared (mid-IR) electrically excited laser. Doping of ZnSe is achieved by varying the mass ratio of zinc chloride (ZnCl₂) or copper selenide (Cu₂Se) to ZnSe precursors in starting pressed powder targets. Appropriate adjustment of the fraction of dopant precursor in the mixtures allows for the control of the dopant concentration, N<i>_D</i>&ndash;N<i>_A</i> for N<i>_D</i> >> N<i>_A</i> (or N<i>_A</i>-N<i>_D</i> for N<i>_A</i> >> N<i>_D</i>) in the thin films, where N<i>_D</i> is the donor concentration and N<i>_A</i> is the acceptor concentration. PLD is used to ablate the Cl:ZnSe or Cu:ZnSe targets, to produce thin films on gallium arsenide (GaAs) substrates. Impedance spectroscopy allows current-voltage and capacitance-voltage (C-V) characterization. Specifically Mott-Schottky measurements determine N<i>_D</i>-N<i>_A</i> (or N<i>_A</i>-N<i>_D</i>) of the fabricated thin film samples with comparisons to the nominal dopant concentration of the targets. The Mott-Schottky, 1/C² vs. V, measurements for determining N<i>_D</i>-N<i>_A</i> were calibrated against well-characterized silicon wafers with known values of N<i>_D</i>. The goal of this project was to demonstrate a reliable method for controlling the dopant concentration in PLD-deposited Cl:ZnSe and Cu:ZnSe thin films. The results obtained allows for the fabrication of Cl:ZnSe and Cu:ZnSe thin films with known N<i>_D</i>-N<i>_A</i> for use in a mid-IR electrically-excited laser devices under development in our research group.</p><p>

This thesis is devoted to quantum confinement effects in low-dimensional Dirac materials. We propose a variety of schemes in which massless Dirac fermions, which are notoriously diffcult to manipulate, can be trapped in a bound state. Primarily we appeal for the use of external electromagnetic fields. As a consequence of this endeavor, we find several interesting condensed matter analogues to effects from relativistic quantum mechanics, as well as entirely new effects and a possible novel state of matter. For example, in our study of the effective Coulomb interaction in one dimension, we demonstrate how atomic collapse may arise in carbon nanotubes or graphene nanoribbons, and describe the critical importance of the size of the band gap. Meanwhile, inspired by groundbreaking experiments investigating the effects of strain, we propose how to confine the elusive charge carriers in so-called velocity barriers, which arise due to a spatially inhomogeneous Fermi velocity triggered by a strained lattice. We also present a new and beautiful quasi-exactly solvable model of quantum mechanics, showing the possibilities for confinement in magnetic quantum dots are not as stringent as previously thought. We also reveal that Klein tunnelling is not as pernicious as widely believed, as we show bound states can arise from purely electrostatic means at the Dirac point energy. Finally, we show from an analytical solution to the quasi-relativistic two-body problem, how an exotic same-particle paring can occur and speculate on its implications if found in the laboratory.

Thesis (Ph.D.)--University of Nebraska-Lincoln, 2008. / Title from title screen (site viewed Aug. 12, 2008). PDF text: vii, 123 p. : ill. ; 2 Mb. UMI publication number: AAT 3297588. Includes bibliographical references. Also available in microfilm and microfiche formats.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2002. / Includes bibliographical references (leaves 47-48). Also available in electronic version. Access restricted to campus users.

Undergraduate honors paper--Mount Holyoke College, 2009. Dept. of Physics. / Includes bibliographical references (leaves 48-49).

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 126-133).

Droplet mobility on surfaces is often hampered by the pinning of the droplet’s contact line. External forces would be needed if motion is to continue. The development of Slippery Liquid-Infused Porous Surfaces (SLIPS) or Lubricant-Impregnated Surfaces (LIS) has since enabled the studies of droplets in low friction situations with virtually no contact angle hysteresis. This thesis presents three separate studies of droplet mobility in the absence of contact line pinning, made possible by the use of SLIPS/LIS. Firstly, the first study of evaporation of sessile droplet under true constant contact angle mode was demonstrated. The lack of contact line pinning meant that droplet’s contact line receded smoothly with no stick-slip stepwise retreat as it evaporated. The absence of a contact angle due to the presence of the wetting ridge around the droplet led to the concept of an extrapolated apparent contact angle. The subsequent study saw the experimental realisation of both inward and outward motion of droplet having an apparent contact angle above 90° confined in a wedge geometry formed by a pair of SLIPS/LIS. Out of equilibrium, droplet was free to travel within the wedge until settling at a prescribed location, regardless to its initial position. This enabled the accurate control over the transport and localisation of the droplet by a reconfiguration of the system. The lack of pinning also suggests that the dynamics of the droplet is dictated purely by viscous dissipation. The final study showed that SLIPS/LIS can be created on macro-patterned surfaces. The macro-patterning introduced menisci features in the impregnating liquid layer which interact with the wetting ridge around a droplet. These interactions were used to induce motion to the droplet. It was also found that accurate positioning of the droplet on an otherwise completely slippery surface can be achieved using well-defined surface topography.