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Optically-Pumped Spin-Exchange Polarized Electron Source, Munir Pirbhai
Optically-Pumped Spin-Exchange Polarized Electron Source, Munir Pirbhai
Department of Physics and Astronomy: Dissertations, Theses, and Student Research
Polarized electron beams are an indispensable probe of spin-dependent phenomena in fields of atomic and molecular physics, magnetism and biophysics. While their uses have become widespread, the standard source based on negative electron affinity gallium arsenide (GaAs) remains technically complicated. This has hindered progress on many experiments involving spin-polarized electrons, especially those using target gas loads, which tend to adversely affect the performance of GaAs sources. A robust system based on an alternative way to make polarized electron beams has been devised in this study, which builds on previous work done in our lab. It involves spin-exchange collisions between free, …
Dynamic Electron Control Using Light And Nanostructure, Wayne Cheng-Wei Huang
Dynamic Electron Control Using Light And Nanostructure, Wayne Cheng-Wei Huang
Department of Physics and Astronomy: Dissertations, Theses, and Student Research
The advent of nano-technology has made possible the manipulation of electron or light through nanostructures. For example, a nano-tip in near-field optical microscopy allows imaging beyond the diffraction limit, and a nano-fabricated hologram is used to produce electron vortex beam. While most schemes of electron control utilize only static components, dynamic electron beam control using both light and nanostructures has not yet been realized. In this dissertation, we explore this possibility and study the interplay between electron, light, and nanostructures. A understanding of such a system may facilitate dynamic electron beam control or even bring new insights to fundamental quantum …
Electron Matter Optics Of The Aharonov-Bohm And Stern-Gerlach Effects, Scot Mcgregor
Electron Matter Optics Of The Aharonov-Bohm And Stern-Gerlach Effects, Scot Mcgregor
Department of Physics and Astronomy: Dissertations, Theses, and Student Research
Since the advent of quantum mechanics and the idea that massive particles exhibit wave properties, physicists have made efforts to make use of the short deBroglie wave length of matter waves for fundamental as well as practical studies. Among these are the precise measurements allowed by interference, diffraction, and microscopy as well as the study of more fundamental aspects of quantum theory such as the Aharonov-Bohm effects or the Stern-Gerlach effect, which are described below. However, in order to use matter waves to observe any of these effects it is necessary to produce and maintain coherence in the waves which …