Magneto-spectroscopy is used to characterize the confinement properties of strain-induced quantum wires and dots. The wires and dots are low energy regions in an ordinary GaAs/AlGaAs quantum well that are formed when microscopic...
Ice mechanics. Compressibility. Fracture mechanics. Strains and stresses. Brittleness.
This work describes the effect of triaxial compressive confinement on the strength of columnar S2 ice loaded under conditions leading to brittle failure. Cubes of columnar S2 ice were tested at -10 °C under triaxial (proportional) loading where...
Robots -- Control systems -- Design and construction. Mobile robots. Robots -- Dynamics.
This thesis examines the issues of vehicle and information dynamics in the control of a multi-robot system using a radial-basis potential function controller. Distributed control of multi-robot systems requires each robot to communicate state...
Electron donor-acceptor complexes. ; Complex compounds. ; Photochemistry.
In this study we have utilized spectroscopic and photoconductivity techniques to investigate free ion formation in the fumaronitrile/trans-stilbene charge transfer-complex. We report free ion yields resulting from the direct excitation of this...
Quantum dots. Heterostructures. Metal oxide semiconductors -- Design and construction. Silicon oxide. Electron gas. Ohmic contacts. Microelectronics -- Technological innovations.
Solid-state approaches to quantum computing include quantum dot qubit implementations based on the Loss-DiVincenzo proposal. Prior work in GaAs two-dimensional electron gas (2DEG) materials serves as a proving ground for device designs that can be...
Si/SiGe quantum dots (QDs) are promising candidates for spin-based quantum bits (qubits) as a result of the reduced spin-orbit coupling as well as the Si isotopes with zero nuclear spin. Meanwhile qubit readout is a challenge related to...
Casimir effect. Zero-point field. Electric conductivity. Quantum electrodynamics.
The Casimir force arises from an alteration of boundary condition in vacuum and is often regarded as a manifestation of quantum zero point energy. Considerable progress has been made in the last decade with an impressive achievement of experimental...
This thesis comprises two separate but related studies, dealing with two strongly interacting nanoscale systems on the border between the quantum and classical domains. In Part 1, we use a Born-Markov approximated master equation approach to study...
Quantum wires and dots can be created by patterning inhomogeneous strain on semiconductor quantum wells. I have used laser spectroscopic methods to study the carrier transfer from the host quantum well to quantum wires and dots. For quantum dot...
Since its discovery in the 1930's, the Cherenkov effect has been paramount in the development of high-energy physics research. It results in light emission from charged particles traveling faster than the local speed of light in a dielectric...
The fluxes of radiation belt electrons are highly variable, due to a competition between various acceleration, loss, and transport processes. Studies of any of the processes are equally important. My study focuses on electron-EMIC (electromagnetic...
We provide a theoretical model for a design involving a dc voltage biased Josephson junction (JJ) that strongly drives a high quality factor microwave cavity via the ac Josephson effect. We explore the rich classical dynamics of the resultant...
Since their discovery in laboratory plasmas in the 1920s, Langmuir waves have been observed to be ubiquitous in plasma environments, particularly in space plasmas. From the greater solar wind to planetary foreshocks and the auroral ionosphere,...
Si-based quantum devices, including Si/SiGe quantum dots (QD), are promising candidates for spin-based quantum bits (quits), which are a potential platform for quantum information processing [1]. Meanwhile, qubit readout remains a challenging task...
The ionosphere is the primary source for heavy ions which are ubiquitous in the terrestrial magnetosphere. Low-altitude energization in the auroral ionosphere results in bulk heating and transverse acceleration of ions, which begin to upwell and/or...
Van Allen radiation belts -- Mathematical models. Electrons -- Diffusion -- Mathematical models. Magnetohydrodynamic waves -- Mathematical models.
It is becoming increasingly important to understand the dynamics of radiation belt energetic particles given their potentially hazardous effects on satellites and our ever-increasing dependence on those satellites. There is a need to determine...
The thesis is dedicated to the understanding and characterization of brittle compressive fracture of columnar S2 ice. The work quantifies the strength of fresh-water S2 ice and investigates its characteristic brittle failure modes under biaxial...
Friction severely limits performance in precise positioning systems. This thesis investigates one possible approach to counter friction related performance losses, friction cancellation. In this method a friction observer is used to estimate...
This thesis presents technologies for the design, fabrication, operation, and control of electrostatic MEMS micro-robots. It describes prototype micro-robots, with dimensions of 60 μm by 250 μm by 10 μm, that are capable of controllable...
Lowest order charged particle motion in the Earth''s magnetosphere can be explained using simple adiabatic theory. However, nonadiabatic theory is required to explain particle behavior in cases such as when the particle's gyroradius is large...
Stark-geometry photorefractive multiple quantum well (PR-MQW) spatial light modulators (SLMs) show promise for several optoelectronic applications such as high-speed image correlation and real-time 3-D holographic imaging. Their performance is...