Physics Commons^™

Exploring Single Particles Through Optical Trapping And Advanced Laser Spectroscopy Techniques, Haifa Hassan Alali

Theses and Dissertations

This dissertation explores the innovative integration of optical trapping (OT) with advanced laser spectroscopy techniques to investigate the physicochemical properties of single particles from a variety of atmospheric aerosols, such as bioaerosols, terrestrial dust, and extraterrestrial dust. Each technique offers unique insights, significantly enhancing our understanding of these critical atmospheric components. The first work focuses on employing OT in conjunction with cavity ringdown spectroscopy (OT-CRDS) to measure the single-particle extinction of interplanetary dust particles at ultraviolet wavelengths (~308 nm). This method allows for the stable trapping of individual dust particles in air, facilitating precise characterization with minimal external interference. Our …

Ge/Sige Quantum Wells: Material For The Post-Moore Era, Troy Alexander Hutchins-Delgado

Optical Science and Engineering ETDs

This dissertation demonstrates high-quality germanium quantum wells on a 200 mm silicon wafer platform, enabling novel device possibilities. Partnering with a commercial silicon-germanium epitaxy supplier, we obtained shallow, undoped germanium quantum wells with high-crystalline quality, confirmed through x-ray diffraction, secondary ion mass spectroscopy, high-resolution scanning transmission electron microscopy, and energy dispersive x-ray spectroscopy. Hall bar devices fabricated on single quantum wells revealed that surface preparation can tune transport properties while maintaining peak mobilities around 10⁵ cm²V⁻¹s⁻¹. Manganese-germanide spintronic contacts were integrated via solid-state reaction, with contact quality assessed through Schottky diodes, transfer length …

Exploring The Accuracy Of Interferometric Quantum Measurements Under Conservation Laws, Nicolò Piccione, Maria Maffei, Andrew N. Jordan, Kater W. Murch, Alexia Auffèves

Mathematics, Physics, and Computer Science Faculty Articles and Research

A (target) quantum system is often measured through observations performed on a second (meter) system to which the target is coupled. In the presence of global conservation laws holding on the joint meter-target system, the Wigner-Araki-Yanase theorem and its generalizations predict a lower bound on the measurement’s error (Ozawa’s bound). While practically negligible for macroscopic meters, it becomes relevant for microscopic ones. Here, we propose a simple interferometric setup, arguably within reach of present technology, in which a flying particle (a microscopic quantum meter) is used to measure a qubit by interacting with it in one arm of the interferometer. …

Exfoliated Hydrotalcite-Transition Metal Complex Composite For Eco-Friendly And Efficient Catalytic Degradation Of 4-Nitrophenol, Sidra Khan, Najma Memon, Saima Q. Memon, Yilmaz Yurekli

Karbala International Journal of Modern Science

Nitrophenols are notorious aquatic organic contaminants found as degradation products of various parent compounds, including pesticides and industrial chemicals that persist in the environment and must be removed. Catalytic degradation is one of the feasible routes to clean the contaminated water systems, however, environmental contamination with catalysts is also widespread. Herein, we report an environmentally friendly catalyst based on composited Fe-Schiff’s base with exfoliated layered double hydroxides (LDH) of aluminum and nickel (hydrotalcite). The composite showed agglomerated pleated LDH structures sheathed with Fe(III)SB. Nitrogen adsorption isotherm data exhibited improved surface area and narrow pores patterns for composite as compared to …

Constructing And Testing Of Photomultiplier Tubes For Coincidence Experiments, Christepher Zamora

Physics Capstone Projects

Muons are particles that can be created by the collision and decay of cosmic rays with the upper atmosphere. Many detectors have been manufactured to detect these particles. This paper describes how muons can be detected. It details the process of constructing and testing of scintillation photomultiplier tubes. This paper also details what was observed during the construction and what was done by the experimenter to correct perceived issues.

Moderate Physical Perspectivalism, Emily Adlam

Philosophy Faculty Articles and Research

Recent developments in the foundations of physics have given rise to a class of views suggesting that physically meaningful descriptions must always be relativized to a physical perspective. In this article, I distinguish between strong physical perspectivalism, which maintains that all facts must be relativized to a perspective, and moderate physical perspectivalism, which maintains that all empirically meaningful descriptions must be relativized to a perspective. I argue that scientific evidence and philosophical considerations support moderate physical perspectivalism over strong physical perspectivalism. In particular, motivations connected to epistemic humility and the social nature of science are more compatible with the moderate …

Rapid Characterization Of Exoplanet Atmospheres With The Exoplanet Transmission Spectroscopy Imager, Luke M. Schmidt, Ryan J. Oelkers, Erika Cook, Mary Anne Limbach, Darren L. Depoy, Jennifer L. Marshall, Landon Holcomb, Willians Pena, Jacob Purcell, Enrique Gonzalez Vega

Physics & Astronomy Faculty Publications

The Exoplanet Transmission Spectroscopy Imager (ETSI) amalgamates a low-resolution slitless prism spectrometer with custom multi-band filters to simultaneously image 15 spectral bandpasses between 430 and 975 nm with an average spectral resolution of R = λ / δ λ ∼ 20 . ETSI requires only moderate telescope apertures ( ∼ 2 m ), is capable of characterizing an exoplanet atmosphere in as little as a single transit, enabling the selection of the most interesting targets for further characterization with other ground and space-based observatories, and is also well suited to multi-band observations of other variable and transient objects. This enables …

Ultraviolet And Blue Stimulated Emission From Cs Alkali Vapor Pumped Using Two-Photon Absorption And Four-Wave Mixing, Ricardo C. Davila, Christopher A. Rice, Nathan B. Terry, Glen P. Perram

Faculty Publications

Stimulated emission on the ultraviolet and blue transitions in Cs has been achieved by pumping via two-photon absorption and four-wave mixing for the pump transition 6²S½ → 8²D_3/2,5/2. The emission performance of the optically pumped cesium vapor laser operating in ultraviolet and blue has been extended to 650 nJ/pulse for 387 nm, 1 to 3 μ J / pulse for 388 nm, 200 nJ/pulse for 455 nm, and 500 nJ/pulse for 459 nm. Emission performance improves dramatically as the cesium vapor density is increased, and no scaling limitations associated with energy pooling or …

Search For Dyson Rings Around Pulsars: Unexpected Light Curves, Ogetay Kayali, Emir Haliki, Kubra Bas, Robert J. Nemiroff

Michigan Tech Publications

Finding Dyson rings around distant pulsars may involve identifying light-curve features that have not been previously identified. Previous studies covered the detection of a ring structure uniformly brightened by the central pulsar, mostly in infrared light. Here, more complex light curves are explored, which arise inherently from the pulsar beam spot’s commonly predicted superluminal speed. These speeds may cause multiple images of the pulsar’s spot on the Dyson ring to appear simultaneously to a distant observer, and so feature bright creation and annihilation events. Therefore, it is possible that even if Dyson ring structures had been observed previously, they might …

Quantum Singular Oscillator With Potential Controlled By Position-Dependent Mass, Elchin Jafarov, Shakir Nagiyev

Turkish Journal of Physics

An exactly solvable model of a nonrelativistic quantum singular oscillator with a controlled potential is constructed. A position-dependent mass is introduced instead of a constant mass of the quantum system under consideration in such a way that it is possible to purposefully control the shape of the potential, turning it into a quantum well with different depths. It is shown that analytical expressions of the wave functions of such a quantum system are described through 2F1 type hypergeometric functions and Jacobi polynomials, whereas, the discrete energy spectrum corresponding to these analytic solutions is non-equidistant. In a specific limit, when the …

Beamed: A Bench For Automated Measurements Of Electrical Discharges - A New Standard For Paschen Curves, Jared Nelson

Doctoral Dissertations and Master's Theses

The initiation of electrical discharges, particularly glow discharges, plays a significant role in industry and environmental science, affecting systems such as electronics, power grids, and atmospheric phenomena. Despite extensive studies and applications of Paschen's law, current methodologies for experimental Paschen tests in direct current (DC) conditions lack standardized practices. This thesis presents the development and validation of a DC-based standard for electrical discharge initiation, using the BEnch for Automated Measurements of Electrical Discharges (BeAMED). BeAMED is designed to standardize the experimental process by automating electrical discharges' initiation and data acquisition. The autonomous nature of the system provides insights into the …

Effect Of Polyacrylamide Gel Elasticity On Collagen Type Ii Fibril Assembly, Kathryn G. Wilcox, Stephanie Kramer, Surajit Chatterjee, Adam Linscott, Sneha Suresh, Lydia Kisley, Svetlana Morozova

Faculty Scholarship

Collagen type II fibrils provide structural integrity to the articular cartilage extracellular matrix. However, the conditions that control the fibril radial size scale, distribution, and formation inside of dense networks are not well understood. We have investigated how surrounding elastic networks affect fibril formation by observing the structure and dynamics of collagen type II in model polyacrylamide gels of varying moduli. Cryogenic transmission electron microscopy (cryo-TEM) is used to image the fibril structure and is verified qualitatively with optical microscopy of fluorescently-tagged collagen within the gels. Using fluorescence correlation spectroscopy super-resolution optical fluctuation imaging (fcsSOFI), the diffusion dynamics of the …

Electricity Generation From Air Movements For Microelectronics Applications, Rahul Nair, Kezang Choden

Australia-Bhutan Research Conference

This paper is about generating limited amount of electricity from natural air movements and air movements in a controlled environment . This is specifically applicable and useful in microelectronics application and as a pre charging . Air is composed of 71% Nitrogen and 21 % oxygen and rest of the gases comprising 8%. We understand that air also takes up from free radicals in the atmosphere due to various chemical reactions. The free radicals and ions have a random motion and movement in the air column. The controlled movement of air with charged particles which is essentially the free radicals …

Source Anisotropies And Pulsar Timing Arrays, Bruce Allen, Deepali Agarwal, Joseph D. Romano, Serena Valtolina

Physics & Astronomy Faculty Publications

Pulsar timing arrays (PTAs) hunt for gravitational waves (GWs) by searching for the correlations that GWs induce in the time-of-arrival residuals from different pulsars. If the GW sources are of astrophysical origin, then they are located at discrete points on the sky. However, PTA data are often modeled, and subsequently analyzed, via a “standard Gaussian ensemble.” That ensemble is obtained in the limit of an infinite density of vanishingly weak, Poisson-distributed sources. In this paper, we move away from that ensemble, to study the effects of two types of “source anisotropy.” The first (a), which is often called “shot noise,” …

A Fourth Planet In The Kepler-51 System Revealed By Transit Timing Variations, Kento Masuda, Jessica E. Libby-Roberts, John H. Livingston, Kevin B. Stevenson, Peter Gao, Shreyas Vissapragada, Guangwei Fu, Te Han, Michael Greklek-Mckeon, Suvrath Mahadevan, Eric Agol, Aaron Bello-Arufe, Zachory Berta-Thompson, Caleb I. Cañas, Yayaati Chachan, Leslie Hebb, Renyu Hu, Yui Kawashima, Heather A. Knutson, Caroline V. Morley, Catriona A. Murray

Pacific Faculty Work

Kepler-51 is a ≲1 Gyr old Sun-like star hosting three transiting planets with radii ≈6-9 R ⊕ and orbital periods ≈45-130 days. Transit timing variations (TTVs) measured with past Kepler and Hubble Space Telescope (HST) observations have been successfully modeled by considering gravitational interactions between the three transiting planets, yielding low masses and low mean densities (≲0.1 g cm⁻³) for all three planets. However, the transit time of the outermost transiting planet Kepler-51d recently measured by the James Webb Space Telescope 10 yr after the Kepler observations is significantly discrepant from the prediction made by the three-planet TTV …

(R2111) Effect Of Stenotic-Aneurysmal Arterial Regime On Unsteady Magnetohydrodynamic Non-Newtonian Blood Flow With Heat Radiation, Babatunde A. Joseph, Dada M. Sunday, Bello A.J. Funsho, Akeem B. Disu, Alamu-Awoniran F., Danas James Y.

Applications and Applied Mathematics: An International Journal (AAM)

The study aims to investigate the effect of magneto-hydrodynamic on a non-Newtonian unsteady blood flow with internal heat energy in the presence of blood ironic properties characterized by stenosis. The formulated mathematical equations resulted in differential forms and were solved analytically by Differential Transform Method. The obtained solutions were displayed by graphs showing different flow physiognomies like blood velocity, temperature profile, Nusselt number, wall shear stress and stream function.

The results indicated that velocity profile increases as magnetic field, Darcy number and aneurysmal artery rise, while it decreases as heat radiation, Reynold number, and Casson parameter speedup. The temperature profile …

A Near-Wall Methodology For Large-Eddy Simulation Based On Dynamic Hybrid Rans-Les, Michael Tullis, D. Keith Walters

Mechanical Engineering Faculty Publications and Presentations

Attempts to mitigate the computational cost of fully resolved large-eddy simulation (LES) in the near-wall region include both the hybrid Reynolds-averaged Navier–Stokes/LES (HRL) and wall-modeled LES (WMLES) approaches. This paper presents an LES wall treatment method that combines key attributes of the two, in which the boundary layer mesh is sized in the streamwise and spanwise directions comparable to WMLES, and the wall-normal mesh is comparable to a RANS simulation without wall functions. A mixing length model is used to prescribe an eddy viscosity in the near-wall region, with the mixing length scale limited based on local mesh size. The …

Characterizing 2d Materials Using Positron Impact Induced Electron Spectroscopy And Development Of A Novel Thin Film Zno Based Piezo-Photonic Detector For Cryogenic And Mems Applications, Pratyanik Sau

2024 Fall Honors Capstone Projects - Archive

Surface analytical techniques are essential for engineering nano-detectors allowing characterization of their chemical composition, electromechanical properties, and physical structure. In the first chapter, the positron impact-induced secondary electron (PIISE) energy spectra and yield from single-layer graphene (SLG) and multi-layer graphene (MLG) grown on a polycrystalline Cu substrate have been presented. In the second chapter, an extensive catalog of Positron Induced Auger Spectra is presented to aid in the analysis of elemental composition of various materials. Additionally, in the third chapter, a novel detection scheme utilizing the piezo-pyroelectric properties of Zinc Oxide (ZnO) thin films have been demonstrated for its application …

Wide-Angle Non-Uniform Optical Phased Array Using Compact And Efficient Antenna Design, Omar E. Elsheikh, Mohamed A. Swillam

Faculty Journal Articles

In the need for a more compact and efficient optical phased array with a wide steering beam for LIDAR applications, a wide steering array with high resolution is desirable. However, in the published work, a trade-off is often made for one over another. Apodized grating antennas have shown good efficiency with a compact size and wide beam profile, which improve optical phased array beam steering capability and are also compatible with the CMOS silicon photonics process. A promising studies shows enhancement in steering range with good resolution utilizing a non-uniform optical phased array. In this work, we present two highly …

Thermal Anharmonicity Of Transition Metals: A Case Study Of Tantalum, Bimal K C

Open Access Theses & Dissertations

Density functional theory (DFT) is commonly used for evaluating the thermal propertiesand equation of state of solids, usually within the quasi-harmonic approximation (QHA). In transition metals, thermodynamic quantities such as the thermal pressure and Gruneisen parameter are poorly reproduced compared with experimental values or with direct computational methods like quantum-molecular dynamics (QMD) simulations. Surprisingly, there has not been to date, a systematic study aimed at understanding the reasons for these discrepancies. Using Tantalum as a case study, we have evaluated the temperature dependence of the phonon frequencies employing Harmonic Ensemble Lattice Dynamics (HELD) combined with classical and quantum molecular dynamics. …

Publisher Correction: Observation Of Dense Collisional Soliton Complexes In A Two-Component Bose-Einstein Condensate (Communications Physics, (2024), 7, 1, (163), 10.1038/S42005-024-01659-W), Sean M. Mossman, Garyfallia C. Katsimiga, Simeon I. Mistakidis, Alejandro Romero-Ros, Thomas M. Bersano, Peter Schmelcher, Panayotis G. Kevrekidis, Peter Engels

Physics Faculty Research & Creative Works

In the first paragraph of the Methods section, the sentence "We begin with an elongated BEC of approximately 9 x 10587Rb atoms…," has erroneously been written without a space between the two superscripts "5" and "87". This has now been corrected in both the HTML and PDF of the article, and the same expression reads: We begin with an elongated BEC of approximately 9 x 105 87Rb atoms…"

Author Correction: Dual Nature Of Magnetism Driven By Momentum Dependent F-D Kondo Hybridization (Communications Physics, (2024), 7, 1, (186), 10.1038/S42005-024-01631-8), Byungkyun Kang, Yongbin Lee, Liqin Ke, Hyunsoo Kim, Myoung Hwan Kim, Chul Hong Park

Physics Faculty Research & Creative Works

Correction to: Communications Physicshttps://doi.org/10.1038/s42005-024-01631-8, published online 12 June 2024 In this article the grant number DE-AC02-07CH11358 relating to Ames National Laboratory was omitted. The original article has been corrected.

Dual Nature Of Magnetism Driven By Momentum Dependent F-D Kondo Hybridization, Byungkyun Kang, Yongbin Lee, Liqin Ke, Hyunsoo Kim, Myoung Hwan Kim, Chul Hong Park

Physics Faculty Research & Creative Works

The intricate nature of magnetism in uranium-based Kondo lattices is a consequence of correlations between U-5f and conduction electrons. Previously, the source of magnetism has been ascribed to either Mott physics or Ruderman-Kittel-Kasuya-Yosida interaction, both of which are not fully applicable to uranium-based Kondo lattices. Using linearized quasiparticle self-consistent GW plus dynamical mean-field theory, we demonstrate a crossover from incoherent to coherent f-d Kondo cloud in the paramagnetic phase of UTe₂, USbTe and USbSe. As the transition occurs, we observe an augmented f-d coherence and Pauli-like magnetic susceptibility, with a substantial frozen magnetic moment of U-5f persisting. We …

Density Effects On The Interferometry Of Efimov States By Modulating Magnetic Fields, G. Bougas, S. I. Mistakidis, P. Giannakeas

Physics Faculty Research & Creative Works

Dynamical association of Efimov trimers in thermal gases by means of modulated magnetic fields has proven very fruitful in determining the binding energy of trimers. The latter was extracted from the number of remaining atoms, which featured oscillatory fringes stemming from the superposition of trimers with atom-dimers. Subsequent theoretical investigations utilizing the time-dependent three-body problem revealed additional association mechanisms, manifested as superpositions of the Efimov state with the trap states and the latter with atom-dimers. The three atoms were initialized in a way to emulate a thermal gas with uniform density. Here, this analysis is extended by taking into account …

Multiphoton-Dressed Rydberg Excitations In A Microwave Cavity With Ultracold Rb Atoms, J. D.Massayuki Kondo, Seth T. Rittenhouse, Daniel Varela Magalhaes, Vasil Rokaj, S. I. Mistakidis, H. R. Sadeghpour, Luis Gustavo Marcassa

Physics Faculty Research & Creative Works

We investigate magneto-optical trap-loss spectroscopy of Rydberg excited Rb85 (66≤n≤68S1/2) atoms, placed inside a tailored microwave cavity. The cavity frequency at 13.053 GHz is in resonance with the 67S1/2→66P3/2 transition, inducing a ladder multiphoton microwave Rydberg absorption and emission. The observed spectra are modeled with an extended Jaynes-Cummings formalism that accounts for nonlinear multiphoton absorption from and emission into the cavity, the loss from the trap due to Rydberg excitation, and cavity imperfection. We calculate the average photons in each spectral feature and find evidence for fractional photon emission into the cavity modes within the loss spectra. The microwave cavity …

Nodal Superconductivity In Miassite Rh17s15, Hyunsoo Kim, Makariy A. Tanatar, Marcin Kończykowski, Romain Grasset, Udhara S. Kaluarachchi, Serafim Teknowijoyo, Kyuil Cho, Aashish Sapkota, John M. Wilde, Matthew J. Krogstad, Sergey L. Bud'ko, Philip M.R. Brydon, Paul C. Canfield, Ruslan Prozorov

Physics Faculty Research & Creative Works

Solid state chemistry has produced a plethora of materials with properties not found in nature. For example, high-temperature superconductivity in cuprates is drastically different from the superconductivity of naturally occurring metals and alloys and is frequently referred to as unconventional. Unconventional superconductivity is also found in other synthetic compounds, such as iron-based and heavy-fermion superconductors. Here, we report compelling evidence of unconventional nodal superconductivity in synthetic samples of Rh₁₇S₁₅ (Tc = 5.4 K), which is also found in nature as the mineral miassite. We investigated the temperature-dependent variation of the London penetration depth Δλ(T) and the disorder …

Clusteredlog: Optimizing Log Structures For Efficient Data Recovery And Integrity Management In Database Systems, Mariha Siddika Ahmad, Brajendra Panda

Electrical Engineering and Computer Science Faculty Publications and Presentations

In modern database systems, efficient log management is crucial for ensuring data integrity and facilitating swift recovery from potential data corruption or system failures. Traditional log structures, which store operations sequentially as they occur, often lead to significant delays in accessing and recovering specific data objects due to their scattered nature across the log. ClusteredLog addresses the limitations of traditional logging methods by implementing a novel logical organization of log entries. Instead of simply storing operations sequentially, it groups related operations for each data item into clusters. As a result, ClusteredLog enables faster identification and recovery of damaged data items …

Graphene-Based Antennas Utilizing Polyvinylidene Fluoride (Pvdf) Substrates For Attenuation, Josef Frankhouse

Mechanical Engineering Undergraduate Honors Theses

In this study, a Terahertz (THz) band antenna which can regulate its own resonant frequency without the requirement of manual adjustment is simulated. A polyvinylidene fluoride (PVDF) substrate is applied onto a rectangular graphene patch antenna. With a voltage potential applied onto the PVDF, the patch antenna can attenuate its frequency by physically changing the shape of the antenna, and in turn its resonant frequency. These antennas are within a 0.1 THz band between 1.32 THz to 1.22 THz measured from a radial bend of a flat surface to r = 75 , fitting into a return loss (S_{11 …}

Ohmic Contacts For Fabrication Of Sic Cmos Devices, Anthony Di Mauro

Graduate Theses and Dissertations

Today’s world of electronics is dominated by semiconductor devices which utilize silicon as their substrate material. Though, silicon is not ideal for semiconductor devices in high-voltage or high-temperature applications. Additionally, the efficiency of silicon devices becomes drastically reduced in nonideal operating conditions. Therefore, finding alternatives to silicon?based devices has been a topic for decades now. A few great candidates to replace silicon devices for said applications include Silicon Carbide (SiC), Gallium Nitride (GaN), and Aluminum Arsenide (AlAs). SiC has grown its reputation as the best candidate, when compared to other potential alternatives, due to its wide bandgap, high operating frequency, …

Fast Neutron & Gamma-Ray Scintillation And Broadband Photoluminescence From Gallium Nitride & Gallium Oxide: Developing Radiation-Hard Diagnostic Platforms, Daniel Jesus Valdes

UNLV Theses, Dissertations, Professional Papers, and Capstones

Integrated scintillation and electronics processing materials are of critical importance in environments exposed to high levels of radiation, such as nuclear fusion diagnostics and space missions. This dissertation focuses on the radiation detection capabilities of gallium oxide (Ga2O3) and gallium nitride (GaN), exploring their responses to fast neutrons and gamma rays. Using high-energy neutron beam facilities at Los Alamos Neutron Science Center (LANSCE) Flight Path 4FP60R, we exposed both Ga2O3 and GaN crystals to neutron irradiation spanning an energy spectrum ranging from 1 to 400 MeV. A Pi-Max 4 fast-gated Intensified CCD (ICCD) camera captured the transient scintillation responses for …