Physics and Astronomy, Department of: Recent submissions
Now showing items 1-20 of 97
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Nonlinear dynamics and shock structures in elongated Bose-Einstein condensates
(2019)Dilute gas Bose-Einstein condensates are ultracold quantum gases that display many peculiar hydrodynamic properties, such as superfluidity, i.e. dissipation-less flow, a variety of solitonic textures and quantized vortex ... -
A study of convex hull optimization and null-stream-based chi squared discrimination statistics for gravitational-wave signal analysis
(2019)We develop data analysis methods to improve the sensitivity of searches for gravitational-wave signals from compact object binaries in networks of ground-based detectors, such as LIGO, Virgo and KAGRA. These are targeted ... -
NONLINEAR PHENOMENA AND STRIPE PHASES IN BOSE-EINSTEIN CONDENSATES
(2019)Dilute-gas Bose-Einstein condensates offer a versatile testbed for the investigation of quantum phenomena. On the mean-field level, these ultracold atomic systems are described by the Gross-Pitaevskii equation which captures ... -
Spectroscopy of Defects in Gallium Oxide
(2019)β-Gallium oxide (β-Ga2O3) is a promising semiconductor for its potential as a material in the field of power electronics. Magnesium doping of Ga2O3 has been shown to create a semi-insulating material, which could be ... -
SPECTRAL MODEL OF RESONANT SOFT X-RAY SCATTERING TO RESOLVE MOLECULE SPECIFIC ORGANIZATION IN 3D ORGANIC NANOSTRUCTURES
(2019)Interest in developing carbon-based materials has increased in recent years due to their advantageous structure and properties. One common challenge in all potential applications is understanding how morphology, in addition ... -
ANHARMONIC PHONON COUPLING AND IN-PLANE HETEROJUNCTION FABRICATION IN 2D IN2SE3
(2019)We study the anharmonic phonon interactions in the single-crystal semiconducting (a) and metal-like (ß) van der Waals In2Se3 layers, through the determination and analysis of temperature-dependent Raman spectra and thermal ... -
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 ... -
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 ... -
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 ... -
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 ... -
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 ... -
Physics Matters, 2017-2018
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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 ... -
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 ... -
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. ... -
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 ... -
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 ... -
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 ...