Physical Sciences and Mathematics Commons^™

Emission Spectroscopy Of Ingaas Quantum Dots Via High-Resolution Fabry-Perot Interferometer, Raju Bhai Kc

Graduate Theses, Dissertations, and Problem Reports

Single photons emitted from self-assembled quantum dots have been widely studied to use as a promising qubit for quantum information processing. Therefore, it is critical to fully understand the emission spectra from the quantum dot's excitation if we want to use a single photon as a quantum bit. It is almost impossible to produce rotationally symmetric quantum dots due to various growth conditions and restrictions. So the real quantum dots do not have a perfectly symmetric structure. A broken rotational symmetry causes an asymmetric exchange interaction between electron and hole, leading to a fine structure splitting between two excited states. …

Characterization And Coherent Spin Selective Manipulation Of Quantum Dot Energy Levels, Tristan Anthony Wilkinson

Graduate Theses, Dissertations, and Problem Reports

Semiconductor quantum dots (QDs) are promising candidates to fulfill a wide range of applications in real-world quantum computing, communication, and networks. Their excellent optical properties such as high brightness, single-photon purity, and narrow linewidths show potential utility in many areas. In order to realize long term goals of integration into complex and scalable quantum information systems, many current challenges must be overcome. One of these challenges is accomplishment of all necessary computing operations within a QD, which might be enabled by coherent manipulation of single QD energy level structures. In the realm of scalability for quantum devices, a way to …

Charge Dynamics Of Inas Quantum Dots Under Resonant And Above-Band Excitation, Gary R. Lander Jr

Graduate Theses, Dissertations, and Problem Reports

Research involving light-matter interactions in semiconductor nanostructures has been an interesting topic of investigation for decades. Many systems have been studied for not only probing fundamental physics of the solid state, but also for direct development of technological advancements. Research regarding self-assembled, epitaxially grown quantum dots (QDs) has proven to be prominent in both regards. The development of a reliable, robust source for the production of quantum bits to be utilized in quantum information protocols is a leading venture in the world of condensed matter and solid-state physics. Fluorescence from resonantly driven QDs is a promising candidate for the production …

Synthesis Of Graphene Using Plasma Etching And Atmospheric Pressure Annealing: Process And Sensor Development, Andrew Robert Graves

Graduate Theses, Dissertations, and Problem Reports

Having been theorized in 1947, it was not until 2004 that graphene was first isolated. In the years since its isolation, graphene has been the subject of intense, world-wide study due to its incredibly diverse array of useful properties. Even though many billions of dollars have been spent on its development, graphene has yet to break out of the laboratory and penetrate mainstream industrial applications markets. This is because graphene faces a ‘grand challenge.’ Simply put, there is currently no method of manufacturing high-quality graphene on the industrial scale. This grand challenge looms particularly large for electronic applications where the …

Evaluation Of X-Ray Spectroscopic Techniques For Determining Temperature And Density In Plasmas, Theodore Scott Lane

Graduate Theses, Dissertations, and Problem Reports

Temperature and density measurements of plasmas are important for understanding various phenomena. For example, equations of state, most scaling arguments for Inertial Confinement Fusion and laboratory astrophysics all rely upon accurate knowledge of temperature and density. Spectroscopy is a non-invasive technique to measure these quantities. In this work we establish a new spectroscopic technique by using it to determine temperature. We also compare and contrast the capability of two codes, PrismSPECT and ATOMIC, to infer electron density from experimentally acquired spectra via Stark broadening.

We compare and contrast the capability of isoelectronic line ratios and inter-stage line ratios in an …

Identification Of Photocurrents In Topological Insulators, Derek A. Bas, Rodrigo A. Muniz, Sercan Babakiray, David Lederman, J. E. Sipe, Alan D. Bristow

Faculty & Staff Scholarship

Optical injection and detection of charge currents is an alternative to conventional transport and photoemission measurements, avoiding the necessity of invasive contact that may disturb the system being examined. This is a particular concern for analyzing the surface states of topological insulators. In this work one- and two-color sources of photocurrents are isolated and examined in epitaxial thin films of Bi2Se3. We demonstrate that optical excitation and terahertz detection simultaneously captures one- and two-color photocurrent contributions, which has not been required for other material systems. A method is devised to extract the two components, and in doing so each can …