Physics Commons^™

An Alternative Approach To Non-Relativistic Quantum Mechanics In Curved Space, Robert A. Hulsey

Dissertations

In the research presented in this dissertation, we propose an alternative formulation of non-relativistic quantum mechanics in curved spaces (Riemannian manifolds). Some toy quantum models (2D quantum harmonic oscillator in Poincaré half-plane model and the flat chart model of hyperbolic 2-space) are studied to understand the physical implications of this alternative formulation.

Using Published Undergraduate Biomechanics Research On Hydra Mouth Opening To Train Undergraduates, Stephen Hackler, T. Goel, Jonah Pacis , '25, Eva-Maria S. Collins

Biology Faculty Works

Biophysics research is exciting because physical approaches to biology can provide novel insights, and it is challenging because it requires knowledge and skills from multiple disciplines. We have developed an undergraduate biophysics laboratory module that teaches fundamental skills such as time-lapse microscopy, image analysis, programming, critical reading of scientific literature, and basics of scientific writing and peer review. The module is accessible to students who are familiar with introductory statistics, cell biology, and differential calculus. We used published research on the biomechanics of Hydra mouth opening as a framework because it describes a stunning biological phenomenon: Hydra, a freshwater …

It’S A Lightboard … And A Glassboard!, Craig Looney

Physics Faculty Publications

In this poster I present an innovative lightboard-glassboard design concept and prototype. The device, when not in use as a lightboard, is positioned against a wall in a low-profile configuration and used as an illuminable office glassboard. For video production, the device – supported and guided by a robust anti-tip rail system – is safely rolled away from the wall and used as a lightboard. This device has several advantages over traditional mobile lightboard designs including ease and reliability of setup, elimination of storage and transport issues, usability in modest-sized offices, and functionality as an illuminable glassboard when not in …

Roles Of Three Conserved Active Site Residues Of Cytochrome C Nitrite Reductases During The Early Steps Of Nitrite Reduction, Shahama Alam, Bradley J. Dimock, Brian Bennett, Steven J. Reinhardt, Shahid Shahid, A. Andrew Pacheco, Jarett Wilcoxen

Physics Faculty Research and Publications

Cytochrome c nitrite reductases (ccNiRs) catalyze reduction of nitrite to ammonium in a six-electron, eight-proton process. This report explores how the behavior of three active site ccNiR variants differs from that of the wild type enzyme (ccNiR_wt) in the presence of nitrite and a variety of electron donors. While the nitrite-loaded active site of Shewanella oneidensis ccNiR_wt could be 2-electron reduced within seconds to yield a 6-coordinate ferrous nitrosyl ({Fe(L)NO}⁷) at high applied potentials, quantitative reduction of the nitrite-loaded variants R103Q, H257Q, or Y206F required substantially stronger reductants and yielded a different product over several …

Aluminum Doped Tin Sulfide Thin Films For Solar Cell Applications, Gabriel Rodriguez Guijarro

Open Access Theses & Dissertations

Tin sulfide (SnS) is theorized to be a suitable material for solar cells, but there are some difficulties that have not been overcome when making thin films that have the properties needed to compete with other materials. This work investigates the structural and optoelectronic properties of aluminum-doped SnS thin films, deposited via magnetron cosputtering physical vapor deposition at different temperatures. To characterize the films a variety of techniques were used: Raman spectroscopy, SEM, TEM, X-Ray Reflectivity, and UV-Vis spectroscopy. The results show that the target stoichiometry is a relevant parameter to take into account when growing SnS thin films, the …

Squeezing Information From Radio Surveys To Probe The Primordial Universe, Dionysios Karagiannis, Roy Maartens, Shun Saito, José Fonseca, Stefano Camera, Chris Clarkson

Physics Faculty Research & Creative Works

A major goal of cosmology is to understand the nature of the field(s) which drove primordial Inflation. Through future observations, the statistics of large-scale structure will allow us to probe primordial non-Gaussianity of the curvature perturbation at the end of Inflation. We show how a new correlation statistic can significantly improve these constraints over conventional methods. Next-generation radio telescope arrays are under construction which will map the density field of neutral hydrogen to high redshifts. These telescopes can operate as an interferometer, able to probe small scales, or as a collection of single dishes, combining signals to map the large …

Quantum Dot Light Emitting Diodes As A Light Source For Photodynamic Therapy, Hamid El Hamidi

Graduate Doctoral Dissertations

ABSTRACT:

QUANTUM DOT LIGHT EMITTING DIODES AS A LIGHT SOURCE FOR PHOTODYNAMIC THERAPY

Photodynamic therapy is a cancer treatment modality that involves the accumulation of a photosensitizer, exposure to visible light, and the presence of oxygen, resulting in the formation of highly reactive and cytotoxic singlet oxygen. PDT has been shown to be more effective as the fluence rate decreases due to oxygen availability and the absence of photobleaching. On the other hand, Quantum Dot Light Emitting Diodes QLEDs- a new form of light source based on nanoparticles (quantum dots)- emerge as a potentially advantageous light source for certain types …

Low Energy Ion Irradiation Effects In Electronic Devices And Materials, David C. Mccall

All Dissertations

The physics and engineering of ion-solid interactions are governed by the ion beam characteristics (flux, charge, energy) and target(s) in question. Here I present work on two projects related to the extraction of a high flux of low charge state Argon ions from a commercial plasma source and the irradiation of an engineered target, a transistor, with high charge state Argon ions.

An end-Hall ion source that produces a a high current plasma of ions and electrons in a rough vacuum environment is characterized. Using a Langmuir probe and multiple pressure measurements, the ion and electron content of the source …

Comparison Of Finite-Amplitude Acoustic Models: Single Equation Of Motion For Potential Vs System-Level Approaches, Mohammad Javad Mohaghegh Kojidi

LSU New Orleans Theses and Dissertations

This study evaluates two finite-amplitude acoustic models, by solving the associated equations of motion (in potential form), and then compares the results with recent studies using hyperbolic system-level approaches. An implicit numerical method is employed to solve the second-order equations in one dimension. The performances of the Diaz et al. (2018) and Blackstock (1963) models in approximating the acoustic special case of the Euler system, via velocity profile plots and related metrics, are evaluated and compared. Working in the setting of the classical signaling problem with sinusoidal input, present results (using the single equation of motion approach) provide independent confirmation …

Induced Helical Anisotropy In Permalloy Thin Films And Patterns, Md Mahmudul Hasan

LSU New Orleans Theses and Dissertations

The goal of this research was to create thin films with induced helical anisotropy and investigate magnetic properties of such films and their patterns. An alloy of 20% iron and 80% nickel (permalloy) was used because of very small magnetocrystalline anisotropy and magnetostriction. First, an unconventional method was used to deposit films with uniaxial anisotropy by sputtering the films onto silicon substrates in the presence of a uniform field of 50 Oe along the substrate plane. This resulted in magnetic atom pairs ordering along direction of the field during film growth. Shapes of hysteresis loops measured at different angles were …

Advancing Lithium-Ion Batteries Through Exploration Of Novel Physico-Chemical Phenomena, Peshal Karki

All Dissertations

Lithium-ion batteries (LIBs) power a wide range of modern devices, from smartphones to electric vehicles. This dissertation integrates materials characterization and electrochemical testing to develop novel Si-based electrode materials, investigate separator effects, and improve electrochemical impedance spectroscopy (EIS) modeling. First, I synthesized Si@CC composites using bio-based carbon sources and discovered a novel in situ disorder reduction in the amorphous carbon cloud during cycling, attributed to Si volume fluctuations and mesoporous carbon structure, which enhanced capacity retention. A binder-free electrode (Si@CC@BP) using bucky paper further improved gravimetric and areal capacities while reducing weight and manufacturing complexity.

Next, I investigated how separator …

Enhanced Point Cloud Generation From A Novel 360° Underwater Lidar, Olagoke E. Daramola

Dissertations

This dissertation presents novel algorithms to improve the mapping capabilities of a 360-degree underwater Pulsed Laser Line Scanner LiDAR (PLLS-360°). Due to its 360° field-of-view (FOV), the PLLS-360° is a compact full-waveform omnidirectional imager suitable for seafloor mapping, underwater asset inspection, object detection, ice-sheet mapping, and construction progress monitoring. The proposed methodology includes an improved waveform fitting technique for saturated waveform recovery, detection array response correction, radiometric corrections, and fusion of LiDAR and sonar bathymetric datasets. The first part of this dissertation assesses the LiDAR’s performance and describes how the data for this unique 360° FOV architecture is processed. The …

Dissipation Physics And Absorption Features In Black Hole X-Ray Binaries, Theodore Dezen Phd, Benjamin R. Cavallari

McNair Summer Research Program

As matter falls closer toward the center of the accretion disk it loses gravitational potential energy, part of which becomes radiation primarily in X-ray wavelengths. Accretion disk models often invoked to fit observed spectra predict relativistically smeared absorption features that are not present in data from black hole X-ray systems such as GX 339-4 and LMC-X3. Informed by recent local and global simulations, we conduct new disk structure and radiative transfer calculations with increased dissipation rates of gravitational potential energy into thermal energy in disk upper layers. We find a noticeable reduction of the absorption features compared to older models …

Investigating Global Lightning Observed From Ground And Space, And Its Relationship To Solar Activity, Megan Diane Mark

Theses and Dissertations

The extremes of lightning, specifically lightning with long-lasting continuing currents and lightning with extremely high peak currents, are investigated from both ground- and space-based observations. Additionally, the potential solar influence on lightning is investigated on large spatial scales.

Continuing currents may occur following the impulsive flow of current during a cloud-to-ground (CG) return stroke and are usually low amplitude (from a few amperes to a few kiloamperes) and long duration (several to hundreds of milliseconds). Remotely estimating their duration from the electromagnetic fields measured by existing ground-based lightning locating systems (LLSs) is not possible, but some space-based lightning detection systems …

Ferroelectricity And Multiferroicity In Ultrathin Films Of Unconventional Transition Metal Oxide, Xin Li

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

Ferroic orders of transition metal oxides, such as ferroelectricity and ferromagnetism, are determined by the intercoupling between spin, charge, lattice. Consequently, ferroic epitaxial thin films have attracted wide interest due to the profuse novel phenomena and the great application potentials for modern electronics. However, the mainstream of the study for transition metal oxides has focused on perovskite structure, limiting the understanding and discovery of novel phenomena associate with ferroic orders. In this thesis, the epitaxial films of hexagonal rare-earth ferrites (h-RFeO₃) and fluorite-structure hafnia oxide (HfO₂) are studied comprehensively, providing new experimental and theoretic …

The Scintillator Surface Detector Of The Pierre Auger Observatory, A. Abdul Halim, P. Abreu, M. Aglietta, I. Allekotte, K. Almeida Cheminant, A. Almela, B. Fick, K. Nguyen, D. Nitz, Et Al.

Michigan Tech Publications

Data collected so far by the Pierre Auger Observatory have enabled major advances in ultrahigh energy cosmic ray physics and demonstrated that improved determination of masses of primary cosmic-ray particles, preferably on an event-by-event basis, is necessary for understanding their origin and nature. Improvement in primary mass measurements was the main motivation for the upgrade of the Pierre Auger Observatory, called AugerPrime. As part of this upgrade, scintillator detectors are added to the existing water-Cherenkov surface detector stations. By making use of the differences in detector response to the electromagnetic particles and muons between scintillator and water-Cherenkov detectors, the electromagnetic …

Unfolding Particle Detector Effects And Solving Qcd Inverse Problem With Generative Ai, Tareq Saeed Alghamdi

Computer Science Theses & Dissertations

Advancements in artificial intelligence (AI) have revolutionized high-energy physics by enabling generative models to address key detector-related Challenges. This work explores the generative model to mitigate smearing, acceptance, and inefficiency in particle detectors, enhancing experimental precision.

We present a generative model-based framework to model and correct detector distortions. Using the Jefferson Lab CLAS g11 experiment as a case study, our approach successfully unfolds detector effects in multi-particle final states while preserving multidimensional correlations despite complex reaction mechanisms. A key focus is addressing the acceptance problem—accurately modeling detector acceptance without computationally expensive simulations. By training generative model-based framework on simulated detector …

Strain Induced Quantum Emitters In Monolayer Wse₂: Fabrication And Characterization Of Dimple Dot Devices, Garrett Maxwell Kitterman

Graduate Theses and Dissertations

Strain induced defects in monolayer tungsten diselenide (WSe₂) give rise to localized exciton funnels, offering a promising approach for the development of tunable quantum emitters. The quantum devices fabricated for this thesis used a modified dimple dot geometry, in which nano indentation creates a strain profile on the monolayer WSe₂. This allows for the funneling of excitons to a confined region. These strain induced funnels enable localized emission from single excitons in WSe₂. Device fabrication was carried out through mechanical exfoliation, dry transfer, and electron beam lithography of Cr/Au gates on a SiO₂ substrate. These devices were then characterized using …

Study On Self-Interaction Errors In Molecular Properties And Magnetic Behaviour Of 2d Materials Under External Stimuli Using Density Functional Theory, Prakash Mishra

Open Access Theses & Dissertations

Density Functional Theory (DFT) has established itself as a practical and versatile method for efficiently studying the properties of materials of solids and molecules. Despite being exact in principle, in practice, DFT calculations rely on an approximation for the exchange-correlation energy functional of the electron density. This results in an erroneous interaction of the electron with itself, known as the self-interaction error (SIE). It arises from the fact that the exchange self-interaction does not exactly cancel out the Coulomb self-interaction. Due to this error, the approximate one-electron potential decays exponentially in the asymptotic region rather than exhibiting the correct ?1 …

Enhancing The Design Of Strained Superlattice Gallium Arsenide Based Photocathodes With Distributed Bragg Reflector, Adam D. A. Masters

Electrical & Computer Engineering Theses & Dissertations

Particle accelerators play a crucial role in our understanding of matter and the universe and have numerous practical applications in various fields. These devices enable scientists to examine the smallest components of matter, study the forces that govern their interactions, and probe conditions from the early universe. Moreover, accelerators are valuable in medicine, industry, and research, enhancing imaging methods, cancer therapies, and manufacturing techniques. As the experiments conducted at these facilities evolve and require higher precision, improved particle sources must continue to advance to keep up with their requirements. To do that, we enhanced the design of spin polarized electron …

Flux Trapping Sensitivity On The Metallurgical State Of Superconducting Radio Frequency Niobium, Bashu Dev Khanal

Physics Theses & Dissertations

Trapped magnetic flux in superconducting radio-frequency (SRF) niobium cavities due to the incomplete Meissner effect is a significant source of rf losses. The relationship between flux expulsion and flux trapping sensitivity to the metallurgical state of 1.3 GHz and 3.0 GHz SRF niobium cavities fabricated from standard and cold-worked Nb sheets and subjected to various heat treatments has been studied. Flux expulsion increased with higher heat treatment temperature in all cavities. Nb cavities made from cold-worked sheets showed better flux expulsion after 800 ◦C/3 h compared to the standard SRF-grade Nb cavities. Similar flux expulsion was observed after annealing at …

Computational Calculations On Zno (0001) And Zno (1010) Surfaces With And Without Pd Adatoms, Amit Aich

Theses and Dissertations

In this research work, first-principles density functional theory (DFT) was used to study O-terminated, Zn-terminated ZnO (0001) surfaces and non-polar ZnO (1010) surfaces. Both clean surfaces and those with Pd or PdO adatoms were examined. Adsorption was considered at O, Zn and hollow sites. After structural relaxation, we analyzed the electronic, optical and adsorption properties. The O-terminated ZnO (0001) surface has a larger band gap of 0.76 eV and p-type conduction. The Zn-terminated surface has a smaller band gap of 0.15 eV and shows n-type behavior. Pd adsorption modifies ZnO’s electronic structure in a site-dependent manner. On O-terminated surfaces, it …

Rabi Oscillations And Entanglement Between Two Atoms Interacting By The Rydberg Blockade And With A Quantized Radiation Field Studied By The Jaynes-Cummings Model, Francisco D. Santillan, Andreas Hanke

Physics & Astronomy Faculty Publications

The interaction between atoms and a quantized radiation field is fundamentally important in quantum optics and quantum information science. Due to their unusual properties, Rydberg atoms are promising building blocks for two-qubit gates and atom-light quantum interfaces, exploiting the Rydberg blockade interaction which prevents two atoms at close distance (< 10μm) from being simultaneously excited to Rydberg states. Recently, this effect was used to engineer quantum processors based on arrays of interacting Rydberg atoms illuminated by Raman lasers. Motivated by these experiments, we extend the Jaynes–Cummings model to study the interaction between two Rydberg atoms interacting by the Rydberg blockade and a quantized radiation field. We consider both number (Fock) states of the field and single-mode quantum coherent states. In particular, we discuss different types of entanglements between various components of the total system consisting of the two Rydberg-interacting atoms and coherent states of the field, and show that the behavior is significantly different compared to a system with non-interacting atoms corresponding to the two-atom Tavis-Cummings model. Our results are relevant in view of atom-light quantum interfaces as components for future long-distance quantum communication.

The Vvv Near-Ir Galaxy Catalogue Of The Southern Galactic Disc, M. V. Alonso, L. D. Baravalle, J. L. Nilo-Castellón, C. Villalon, M. Soto, M. A. Sgro, I. V. Daza-Perilla, C. Valotto, M. Lares, Lucas M. Macri

Physics & Astronomy Faculty Publications

Context. The distribution of galaxies in the zone of avoidance (ZoA) is incomplete due to the presence of our own Galaxy.

Aims. Our research is focussed on the identification and characterisation of galaxies in the ZoA, using the new near-infrared (NIR) data from the VVVX survey in regions covering the southern Galactic disc (230° <  l <  350°).

Methods. We used our previously established procedure, based on photometric and morphological criteria, to identify galaxies. The large data volume collected by the VVVX required alternatives to visual inspection, including artificial intelligence techniques such as classifiers based on neural networks.

Results. The VVV NIR galaxy …

Insights Into The Radiation Chemistry Of Flash Radiation Therapy, Alan E. Lopez Hernandez

Dissertations and Theses (Open Access)

Purpose: FLASH radiation therapy (FLASH-RT) is an emerging modality that delivers radiation at ultra-high dose rates (UHDR) and has shown consistent normal tissue sparing while preserving tumor control compared to conventional RT—a phenomenon termed the FLASH effect. Despite promising results, the mechanisms behind the FLASH effect remain unclear. Many hypotheses point to radiolytic interactions, but experimental validation is limited. This work aims to develop a robust experimental platform to evaluate the relationship between radiolytic species production and physical beam parameters relevant to FLASH-RT, alongside dosimetry tools for reliable UHDR beam characterization.

Methods: A beam collector (BC) Faraday cup detector was …

Facilitating The Clinical Translation Of Flash Radiotherapy Through Dosimetry Development And Beam Parameter Optimization, Kevin Liu

Dissertations and Theses (Open Access)

Advisory Professor: Emil Schüler, PhD

Radiation therapy (RT) is a crucial component of curative cancer therapy, with a majority of cancer patients in the United States receiving RT as part of treatment. The goal of RT is to maximize the therapeutic index in curing disease while minimizing any associated normal-tissue complications¹. Recently, ultra-high dose-rate (UHDR) RT (mean dose rates ≥40 Gy/s for a total duration of ≤200 ms) has been reported to selectively spare normal tissues and organs while maintaining an isoeffective tumoricidal effect compared to conventional (CONV) dose rate RT in a variety of in vivo preclinical …

Measurements And First Principles Calculations On The Non-Centrosymmetric Superconductor Aupb3, Meena Shrestha

Dissertations

AuPb₃ is a non-centrosymmetric superconductor that crystallizes in a tetragonal structure and undergoes a superconducting transition at 4.4 K. Non-centrosymmetric superconductors that lack inversion symmetry are predicted to have an admixture of spinsinglet and spin-triplet symmetry induced by strong antisymmetric spin-orbit coupling (ASOC).

In this work, we investigated the normal and superconducting properties of AuPb₃. We also carried out the Density Functional Theory (DFT) calculations to study the strength of ASOC and its impact on vibrational and electronic properties. A high-quality polycrystalline sample of AuPb₃ was grown and characterized by powder x-ray diffraction, scanning electron microscopy, …

Development Of A New Groundbased Instrumentation Technique For Low-Resolution Exoplanet Transmission Spectroscopy, Mary Anne Limbach, Luke M. Schmidt, Ryan J. Oelkers, Darren L. Depoy

Physics & Astronomy Faculty Publications

We present a new instrumentation technique for high-precision, ground-based spectrophotometric measurements ideal for low-resolution (R ∼ 20–60) exoplanet transmission spectroscopy. This technique employs novel thin-film coating technology for wide-band, simultaneous multi-band imaging, enabling high-precision differential photometry through self-referencing and comparison stars. Theoretical calculations and on-sky results show that this method effectively reduces 96% of amplitude scintillation noise and other systematics that typically limit ground-based spectrophotometric precision for bright stars. On-sky results are demonstrated using the custom-built Exoplanet Transmission Spectroscopy Imager (ETSI), deployed at the McDonald Observatory 2.1 m telescope in 2022. For a V = 9.7 mag star, ETSI …

An Investigation Into The Principle Of Symmetric Criticality, Guillermo Frausto

All Graduate Theses and Dissertations, Fall 2023 to Present

In physics, symmetries help us understand complex systems by revealing conserved quantities and simplifying equations. In the context of general relativity, where spacetime is curved and dynamic, these symmetries become especially important when trying to reduce or solve the equations that govern gravitational and matter fields.

This dissertation investigates a mathematical principle known as the Principle of Symmetric Criticality (PSC), which helps determine when symmetries can be used to simplify physical theories without losing essential information. While often assumed to be valid, PSC does not always hold, and understanding when it does is critical for the reliable use of symmetry …

Advancing Real-World Implementation Of The Well Optimized Linear Finder (Wolf) High-Speed Atmospheric Turbulence Compensation Method, Timothy Evan Coon

Theses and Dissertations

This dissertation advances the real-world implementation of the Well Optimized Linear Finder (WOLF) method for high-speed Atmospheric Turbulence Compensation (ATC). Atmospheric turbulence introduces phase aberrations into optical wavefronts and degrades image quality in terrestrial imaging systems. Traditional phase diversity methods are computationally intensive and poorly suited to real-time operation. The WOLF method addresses these limitations through a novel, point-wise formulation of the optical transfer function (OTF) as a structured autocorrelation of the generalized pupil function (GPF). This formulation enables the estimation of phase aberrations at individual spatial coordinates with distributed computational complexity.

The research begins by developing a MATLAB-based simulation …