Physics and Astronomy, Department of: Recent submissions
Now showing items 1-20 of 91
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Research Group Data Archive, 1985-2018
(2018-09)Included here are two parallel archives, one of raw spectral DATA and the other of spectral ANALYSIS. There is a small number of other spectra, such as of positron lifetimes, x-ray diffractograms, “DATA” contains raw ... -
Physics Matters, 2017-2018
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ANALYTIC RELATIONS BETWEEN CLASSICAL ORBITS IN CHAOTIC SYSTEMS, AND THEIR IMPLICATIONS FOR QUANTUM CHAOS
(2018)Rare sets of classical orbits, such as the heteroclinic and periodic orbits, play central roles in various semiclassical sum rules, in which they sum up in interference-like ways to determine spectral quantities of quantum ... -
Application-driven studies of photomechanical materials
(2018)Deep brain stimulation therapy is a well-established medical procedure with well-documented benefits, but this procedure would be enhanced by a flexible therapy device that could bend when photoactivated. To this end, two ... -
ELECTRICAL AND THERMOELECTRIC PROPERTIES OF VAN DER WAALS HETEROSTRUCTURES
(2018)Two-dimensional (2D) layered semiconductors, particularly the transition metal dichalcogenides (TMDs), have been extensively explored as the material of choice for applications in electronics and optics. However, the ... -
CVD GROWTH AND RAMAN SPECTROSCOPY STUDY OF VAN DER WAALS IN2SE3
(2018)Using micro-Raman spectroscopy and finite-element simulations, we determine the in-plane thermal conductivity of suspended two-dimensional single-crystal In2Se3 grown by chemical vapor deposition. The thermal conductivity ... -
Solute-solute interactions in intermetallic compounds studied using perturbed angular correlation of gamma rays
(2017-05)Interactions between pairs of solute atoms dissolved in a binary intermetallic compound were studied. Perturbed angular correlation of gamma rays (PAC) was used to detect solute atoms next to impurity PAC probe atoms in ... -
Dispersion Engineering of Bose-Einstein Condensates
(2017)The subject of this dissertation is engineering the dispersion relation for dilute Bose-Einstein condensates (BECs). When a BEC is immersed into suitably tailored laser fields its dispersion can be strongly modified. ... -
Nonlinear optics near the fundamental limits
(2017)The nonlinear optical response of materials on the fastest time scale is ultimately determined by the quantum mechanical properties of the material's electronic configuration. This response is limited by the amount of ... -
Extending Miedema's Semi-Empirical Model to Predict Defect Site Preferences and Formation Enthalpies of Ordered Compounds
(2016-12)Miedema's Semi-Empirical Model is a method in which a simple calculation provides a rough estimate of the formation enthalpy of a single defect atom (of element X) surrounded completely by a solvent element (element A). ... -
A qualitative look at the thermodynamics of ternary phase diagrams
(2016-05)In 2014, Collins’ research group embarked on experiments using Perturbed Angular Correlation (PAC) spectroscopy to measure interactions between solute atoms in ternary alloys. PAC requires a probe atom, 111In, making the ... -
Helically-Supported Capillary Channels as Liquid Acquisition Devices in Microgravity
(2016)Fluid-filled springs are capillary channels that can be used as liquid acquisition devices to passively separate two-phase systems in microgravity. However, these channels must be primed and connected to a pressure reservoir ... -
Persistant Photoconductivity of Strontium Titanate
(2016)Strontium titanate (SrTiO$_3$) is a transparent conducting oxide with a range of interesting properties, including a large, temperature-dependent dielectric constant and superconductivity at low temperatures. It has a wide ... -
Electrical and Optoelectronic Properties of Two-Dimensional Materials
(2016)Electrical and optoelectronic properties of bulk semiconductor materials have been extensively explored in last century. However, when reduced to one-dimensional and two-dimensional, many semiconductors start to show unique ... -
Pressure-Induced Phase Transitions of Indium Selenide
(2016)In2Se3 has potential as a phase-change material for memory applications. Understand- ing its phase diagram is important to achieve controlled switching between phases. Pressure-dependent phase transitions of In2Se3 bulk ... -
Investigations of ternary alloys using perturbed angular correlations
(2015-06)The intended goal of this research was to investigate interactions between solute atoms in intermetallics using a nuclear probe method, Perturbed Angular Correlation (PAC) of gamma rays. The PAC probe, radioactive 111In, ... -
INVESTIGATING [X/FE], IMF AND COMPOSITENESS IN INTEGRATED MODELS
(2015)This dissertation explores several existing challenges of evolutionarystellar population synthesis models in integrated light:age-metallicity degeneracy, initial mass function (IMF), elementalabundances, and compositeness. ... -
Understanding Molecular Machines: Theoretical and Experimental Approaches
(2015)This dissertation concerns the study of two classes of molecular machines from a physical perspective: enzymes and membrane proteins. Though the functions of these classes of proteins are different, they each represent ... -
ULTRAFAST CARRIER DYNAMICS IN THIN FILM HYDROGENATED AMORPHOUS SILICON AND SILICON-GERMANIUM ALLOYS
(2015)This dissertation presents an investigation of the ultrafast carrier dynamics in thin film hydrogenated amorphous silicon (a-Si:H) and silicon germanium alloys (a-Si_(1-x) Ge_x:H). These materials have attracted considerable ...