Condensed Matter Physics Commons^™

Probing Symmetry And Disorder Effects In The Fractional Quantum Hall States Of The Second Landau Level, Ethan I. Kleinbaum

Open Access Dissertations

Electrons confined to two dimensions, cooled to cryogenic temperatures, and placed in a strong perpendicular magnetic field exhibit a set of ground states referred to as the fractional quantum Hall states (FQHS). The FQHSs forming in the region called the second Landau level are some of the most exciting states as several theories predict that they are very different from the well understood FQHS in the lowest Landau level. Nonetheless, the nature of these FQHSs continue to evade understanding. In this thesis, a unique ultra-low temperature setup is used to examine the FQHSs of the second Landau level in regimes …

Localization And Delocalization In Two-Dimensional Quantum Percolation, Brianna S. Dillon Thomas

Open Access Dissertations

Quantum percolation is one of several disorder-only models that address the question of whether conduction, or more generally, delocalization, is possible in two dimensional disordered systems. Whether quantum percolation exhibits a delocalization-localization phase transition in two dimensions is an ongoing debate, but many recent studies point toward there being a delocalized phase at non-zero disorder, in contradiction to the behavior of the Anderson model, another disorder-only model. In this dissertation, I present my research on quantum percolation that shows a delocalized state is possible, both on isotropic lattices and on highly anisotropic lattices, and shows that the essential characteristics of …

Energy Transfer And Localization In Molecular Crystals, Mitchell A. Wood

Open Access Dissertations

With the aim of developing new technologies for the detection and defeat of energetic materials, this collection of work was focused on using simulations to characterize materials at extremes of temperature, pressure and radiation. Each branch of the work here is collected by which material response is potentially used as the detectable signal.

Where the chemical response is of interest, this work will explore the possibility of non-statistical chemical reactions in condensed-phase energetic materials via reactive molecular dynamics (MD) simulations. We characterize the response of three unique high energy density molecular crystals to different means of energy input: electric fields …

Fabrication And Photonics Properties Of Iii-V Semiconductor Nanowire Structures, Tzu-Ging Lin

Open Access Dissertations

III-V semiconductor nanowires (NWs) have shown great potential to be building blocks for optical, optoelectronic, and electronic devices due to their special transverse confinement of electrons and photons along the nanowire axis. In addition, semiconductor nanowires with subwavelength structures exhibit strong optical Mie resonance, making them ideal platforms for realizing novel optical devices, such as extreme solar energy absorbers and broadband light trapping devices. This special 1D optical Mie resonance can be enhanced by using semiconductor-core dielectric-shell (CS) and metal-core semiconductor-shell dielectric-outer shell (CSS) nanowire heterostructures. Those advantages can be even leveraged up by utilizing nanowire arrays, attributing to the …