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Free Charge Carrier Properties In Two-Dimensional Materials And Monoclinic Oxides Studied By Optical Hall Effect, Sean Knight

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In this dissertation, optical Hall effect (OHE) measurements are used to determine the free charge carrier properties of important two-dimensional materials and monoclinic oxides. Two-dimensional material systems have proven useful in high-frequency electronic devices due to their unique properties, such as high mobility, which arise from their two-dimensional nature. Monoclinic oxides exhibit many desirable characteristics, for example low-crystal symmetry which could lead to anisotropic carrier properties. Here, single-crystal monoclinic gallium oxide, an AlInN/GaN-based high-electron-mobility transistor (HEMT) structure, and epitaxial graphene are studied as examples. To characterize these material systems, the OHE measurement technique is employed. The OHE is a physical …

Single-Neutron Transfer To 50ti, Jessica Nebel-Crosson

Physics and Astronomy Summer Fellows

This is a continuation of the data analysis of a neutron-transfer reaction with ⁵⁰Ti, in which the data was collected in 2019 and this analysis focuses on automating the calibration and peak fits for the generated spectra. Future work will continue with producing angular distributions for the rest of the excitation states and further analyzation in order to draw conclusions about single-neutron state structures.

Many Body Localization With Rydberg Atoms, Alicia Handian

Physics and Astronomy Summer Fellows

Systems are known to thermalize, or reach equilibrium, with the passing of time. However, when this does not occur, the quantum states of the system may be localized. Localized states carry information of the system’s initial state that is typically lost during the process of thermalization. We aim to study thermalization and localization in systems of rubidium Rydberg atoms, and to further understand these phenomena via simulation while we are developing a more refined experiment.

Measurement Of Inclusive Fiducial And Differential Cross Sections In The H → Zz∗ → 4l Decay Channel In P-P Collisions At 13 Tev With The Full Atlas Run 2 Dataset, Madalyn Mckay

Physics Theses and Dissertations

The Higgs boson inclusive and differential fiducial cross sections are measured in the H → ZZ∗ → 4l, decay channel, where l = e,μ. The measurements are performed using proton−proton collision data from the Large Hadron Collider produced at a center-of-mass energy of 13 TeV. The data was recorded by the ATLAS detector between 2015 and 2018 and corresponds to an integrated luminosity of 139 fb⁻¹. Differential fiducial cross sections are measured for a set of observables that are sensitive to the production and decay of the Higgs boson. All measured cross sections are found to be in …

Learning Assistant And Instructor Communication: Impacts On Perceived Efficacy, Jahangir Rassouli, Laura Ríos

Physics

The Learning Assistant (LA) Model was co-developed by Richard McCray and Valerie Otero at the University of Colorado Boulder in 2003. In this model, senior undergraduate students serve as facilitators for group discussion in lower-division courses, and employ evidenced-based practices for promoting inquiry and active learning [1]. Since its inception, the LA model has grown to various departments, disciplines, and universities.

At California Polytechnic State University San Luis Obispo (Cal Poly), the LA program in the physics department is still in its early stages. As such, it is an environment rich for exploration into the affordances, limitations, and benefits of …

Long Lived Second Mode Internal Solitary Waves In The Andaman Sea, J.M. Magalhaes, J.C.B. Da Silva, Maarten C. Buijsman

Faculty Publications

Internal waves are density oscillations propagating along the ocean’s inner stratification, which are now acknowledged as a key constituent of the ocean’s dynamics. They usually result from barotropic tides, which flow over bottom topography, causing density oscillations to propagate along the pycnocline with a tidal frequency (i.e. internal tides). These large-scale waves propagate away from their forcing bathymetry and frequently disintegrate into nonlinear short-scale (higher-frequency) internal wave packets. Typically, short-scale internal wave observations in the ocean are associated with vertical structures (in the water column) of the lowest fundamental mode. Higher vertical modes have recently been documented as well, but …

Mechani-Kits Senior Design Project, Jake Utley, Sophie Carson, Vincent Seguin

Mechanical Engineering

Studies suggest that when designed and executed well, hands-on activities can enhance student understanding of key mechanics concepts. Current products are expensive and typically not designed to meet a variety of learning objectives. Through the Mechanics of Inclusion and Inclusivity in Mechanics grant, the Cal Poly Physics and Engineering Departments are seeking to incorporate new hands-on activities into their courses. Our team has designed three inexpensive ”MechaniKits” to be used in physics, statics and dynamics courses [1]. This Final Design Review outlines our findings, objectives, and final designs for this project. It also explains our manufacturing and design verification plans. …

Methods For Sensitive Detection Of Magneto Optic Kerr Effect, James Creed

Master's Theses

The focus of this project is to numerically model the phenomenon known as the Magneto Optic Kerr Effect, MOKE, where the interaction between light and surface in the presence of a magnetic field, results in a rotation of the polarization axis of the reflected light, and to develop a method by which to experimentally measure the strength of the interaction. The amount of polarization rotation is proportional to the strength of the magnetic field and changes in polarization can be detected using polarizing optics. This thesis project successfully develops a numerical model for MOKE and an experimental method is outlined …

Phys 121-450: Physics Ii, Ion Cohanoschi

Physics Syllabi

No abstract provided.

Phys 102-450: General Physics, Keun Hyuk Ahn

Physics Syllabi

No abstract provided.

Phys 121-451: Physics Ii, Kushal Shrestha

Physics Syllabi

No abstract provided.

Demonstrating And Testing The Deutsch-Jozsa Quantum Algorithm Towards The Realization Of Quantum Computing At Bsu, John J. Gilmore Jr.

Honors Program Theses and Projects

The world is changing, and fast. Quantum computing and photonic engineering are revolutionary new technologies that could change the way humans interact with information; though the eld hasn't always been that way. As with most new elds, proof of concept is needed to show that this new technology isn't just hear to stay, but it's hear to take the lead. In this, nothing is more important the the Deutsch-Jozsa Quantum algorithm; as it did just that . The majority of this research paper revolves around understanding the very essence of quantum computing. As the eld of quantum computing is in …

Examining The Effect Of El Nino Phenomena And Pacific Sea Surface Temperature On The Climate Of The Glacierized White Mountains In Peru, Emily Reardon

Honors Program Theses and Projects

The purpose of this study is to determine if there is a correlation between the El Ni~no Southern Oscillation, sea surface temperatures (SST) and the climate of the Rio Santa Basin. This study is an important step in understanding the dynamics of the glaciers as a critical control on hydrological features in alpine Andes Valleys. Temperature and precipitation measurements pulled from ground based weather stations in the Rio Santa drainage basin were aggregated, synchronized, and correlated with the changes in the Pacific ocean SST o the coast of Peru and into the central Pacific. The expectation is that we will …

The Effect Of Chirality On Dna Threading: Exploring Binuclear Ruthenium Lntercalators Using Optical Tweezers, Adam A. Jabak

Honors Program Theses and Projects

Using optical tweezers, we have been able to study the interactions of small molecules and prospective cancer drugs with DNA. One type of these molecules, known as threading intercalators, has a flat planar intercalating moiety in between the molecule’s bulky ancillary supporting ligands. In order to bind with DNA, they have to thread their bulky ancillary ligands in between the DNA base pairs. Due to this requirement for binding, these molecules tend to have high binding affinities and slow kinetics. In this thesis, we explore the binding properties of a ruthenium-based threading intercalator -[μ-bidppz(phen)4Ru2]4+, or -P for short. The goal …

Image Processing Of Narrow Band Solar Eclipse Data Using Python And Maxim Dl, Rydia Hayes-Huer

Honors Program Theses and Projects

On July 2, 2019, a total solar eclipse (TSE) was observable from Chile and Argentina. In Chile, I worked alongside the Solar Wind Sherpas, an international group led by Dr. Shadia Habbal from the University of Hawai'i Institute for Astronomy, to make observations of the solar corona and gather information about its elemental composition. Narrow band data were collected for Fe XI, Fe XIV, and Ar X. Data collected during TSE observations can be used to help solve two puzzles in solar physics: the coronal heating problem and the mechanisms responsible for the fast and slow solar winds. Narrow band …

Building A Light Current Voltage Characterization Setup For Pulsed Laser Diodes, Alec A. Milford

Honors Program Theses and Projects

III-V laser dies are the main integrated light sources used in photonic integrated chips (PIC). Before incorporating these lasers in PICs, it is important to measure their performance and efficiency. The efficiency of these devices can be calculated from their light-current-voltage (L-I-V) characteristics. In this thesis, I will assemble the components of the probe station for the pulsed LIV setup, which are the pulse generator to drive the laser with current, temperature controller device to vary the laser’s operating temperature, and optical spectrum analyzer in order to characterize the laser’s emission wavelength. Initially this thesis was meant to report how …

College Student Changing Attitudes And Beliefs About The Nature Of And Teaching Of Mathematics And Science, Stephen R. Skinner

Graduate Theses and Dissertations

With an estimated 17.3 million STEM jobs in the US, there exists a need for a STEMready workforce that is science literate with positive attitudes and beliefs toward the learning and teaching of mathematics and science (Graf, Fry, & Funk, 2018). However, the US has seen a steady decline in the number of high school students interested in STEM-related fields with only 16% of interested students with proven proficiency in mathematics and science and are ready to enroll in college STEM programs (ACT, 2017; Osborne & Dillon, 2008; Stake & Mares, 2001). With the decline in student interest, the US …

Determining The Rotational And Orbital Velocities Of Objects In The Solar System, Mark Jones

Undergraduate Honors Theses

Astronomers have been observing the night sky for many centuries to establish a better understanding for our universe and solar system. As part of their observations, astronomers characterize celestial bodies by fundamental properties such as mass, motion, and composition in order to provide further insight about the objects in question. As technology and science have evolved, the methods for measuring these properties have become more precise and accurate. One such methodology is known as spectroscopy, and it is a significant tool for observational astronomy. In this paper, we shall describe how we used astronomical spectroscopy to determine orbital and rotational …

Measurements Of Radio Pulse Reception With Stations Of The Ara Experiment Based On The Spicecore Pulser Data Set, Jesse Osborn, Ilya Kravchenko

UCARE: Research Products

The Askaryan Radio Array Experiment located near the South Pole works to pinpoint specific instances of neutrinos from outside the solar system interacting with nucleons inside the Antarctic ice. Neutrinos are a subatomic particle that has nearly no mass and a net neutral charge. As they are, neutrinos tend not to interact with anything as they travel through space which means they can provide us with information about events occurring far from Earth that might not be easily attained through other methods. Neutrinos are known to be emitted from a myriad of sources, including the Sun, the interaction between cosmic …

Understanding The Spin-Glass State Through The Magnetic Properties Of Mn-Doped Znte, A. Alcantara, S. Barrett, D. Matev, I. Miotkowski, A. K. Ramdas, T. Pekarek, J. T. Haraldsen

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Magnetic measurements on the spin-glass behavior in the bulk II-VI diluted magnetic semiconductor (DMS) ZnMnTe were made on two crystals of concentrations x = 0.43 and 0.55 taken from the same boule. Magnetization and density functional theory studies have shown paramagnetic behavior in both samples between 30 and 400 K. Below 30 K, there is a prominent peak at Tc = 15 and 23.6 K for concentrations x = 0.43 and 0.55, respectively. The splitting of the field cooled (FC) and zero field cooled (ZFC) data below this peak is indicative of a transition to a spin-glass state at low …

Reduced Dimensionality Effects In Ferromagnetic Behavior In La1-Xsrxmno3, C. A. Brennan, M. P. Warusawithana, J. Payne, D. Brown, T. M. Pekarek

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

We study the magnetic properties of La1-xSrxMnO3 samples for concentrations x, 0 ≤ x ≤ 0.5. An analysis is done to accurately determine the transition temperature or critical temperature. Magnetic phase diagrams showing the various concentrations at different temperatures will be determined for our thin films. Using the phase diagrams for both bulk and thin film materials can show how reducing the dimensionality from the third dimension to approaching the second-dimension affects the phase diagram.

Understanding The Magnetic Interactions Of The Zig-Zag Honeycomb Lattice: Application To Rucl3, Evan Wilson, Jason T. Haraldsen

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

The new field of Dirac quantum matter has produced a lot of interesting theories and materials, especially in the dynamics of magnetic materials. One such material is RuCl3, which is a S = 1/2 zigzag honeycomb lattice. Through inelastic neutron scattering, this material has demonstrated spin waves with an energy scale of 1.5-8.0 meV. According to literature, RuCl3 may be the realization of a new theoretical phase of matter called a spin liquid. This materials seems to fit the profile and has been investigated using a Kitaev model. In this study, we re-examine the data for RuCl3 using a standard …

Extended Gamma Analysis Of Snr G330.2 + 1.0, Abagael Barba, John W. Hewitt

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Analyzing gamma rays is an important aspect of modern astronomy and astrophysics, for they are the most powerful bands of energy on the electromagnetic spectrum. Comprehending gamma rays allows for deeper understanding of countless phenomena within our universe, such as cosmic rays. Cosmic rays are high energy particles thought to be formed via extremely violent explosions within our universe. These accelerated particles mirror conditions present in a supernova. A supernova is what occurs when a star at least 8 times as massive as our sun reaches the end of its lifespan and bursts. These explosions are the most powerful events …

Identification Of Histone H4-Based Peptoids As Inhibitors Of Prmt1, Megan Demart, Molly Dubose, Sarah Mann, Corey Causey Phd, Bryan Knuckley Phd

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Protein Arginine Methyltransferases (PRMTs) are a family of 11 mammalian enzymes characterized by the post-translational methylation of arginine residues in the histone tail. The majority of the 11 members of the PRMT family are divided into two main types, Type I and Type II. PRMT1, the major Type I isozyme, catalyzes the formation of asymmetrically dimethylated arginine (ADMA). PRMT1 activates transcription of cancer genes. Peptoids, or poly-N-substituted glycine’s are a class of oligomers whose side chains are appended to the nitrogen atom of the peptide backbone rather than the alpha carbon. Kinetic parameters were conducted for both peptide and peptoid …

Investigation Of The Obscure Spin State Of Ti-Doped Cdse, J. Dimuna, T. Boyett, I. Miotkowski, A. K. Ramdas, T. Pekarek, J. T. Haraldsen

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Using computational and experimental techniques, we examine the nature of the 2+ oxidation of Ti-doped CdSe. Through stoichiometry and confirmed through magnetization measurements, the weakly-doped material of Cd1-xTixSe (x = 0.0043) shows the presence of a robust spin-1 magnetic state of Ti, which is indicative of a 2+ oxidation state. Given the obscure nature of the Ti2+ state, we investigate the electronic and magnetic states using density functional theory. Using a generalized gradient approximation with an onsite potential, we determine the electronic structure, magnetic moment density, and optical properties for a supercell of CdSe with an ultra-low concentration of Ti. …

Investigating The Substrate Specificity Of Prmt1 Using A Plate Based Screening Method, Tina Sawatzky, Sarah Mann, Bryan Knuckley

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Enzymes are biological catalysts that speed up the rate of a reaction by lowering the activation energy and converting substrate (reactant) to product more expeditiously. Enzymes have a high degree of specificity and will only catalyze selective reactions by targeting particular substrates. In mammals, there exists a family of 11 enzymes, PRMT’s (Protein Arginine Methyl transferase), that target protein arginine for post translational methylation on the guanidino nitrogen of the residue. They occur naturally as Type I, II and III and can administer asymmetric di-methylation (ADMA), symmetric dimethylation (SDMA) and monomethylation, respectively. The focal point of this project is to …

Electronic And Magnetic Order As A Function Of Doping In Mixed-Valent La1-Xsrxmn03 Thin Films, James Payne, Dakota Brown, Calleigh Brannan, Tom Pekarek, Maitri Warusawithana

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

The rich phase diagram in mixed-valent manganites has been intensely studied in bulk crystals as a function of chemical doping. Here we study the effect of doping in La1-xSrxMnO3 thin films by varying the Sr/La ratio between samples. These thin films are grown using ozone assisted molecular beam epitaxy with carefully controlled stoichiometry for a range of doping from x = 0.0 to x = 0.5. Our electronic measurements reveal a crossover from a Mott insulator to a metallic ground state as x is increased. In the metallic ground state we observe a metal-to-insulator transition coincident with a ferromagnetic-to-paramagnetic ordering …

Improving Photon Number Resolution In Superconducting Nanowire Single-Photon Detectors With Integrated Impedance Tapers, Bladimiro E. Valbuena, Daniel F. Santavicca

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Simulations are run to optimize the ability to resolve the number of photons detected from the pulse height by a Superconducting Nanowire Single-Photon Detector (SNSPD). This is set up in a manner that features an impedance-matching transmission line taper that provides a characteristic impedance which transitions from kΩ to 50 Ω, with the taper providing an effective load impedance that outputs pulses with not only larger amplitudes but also showed a distinct separation for multi-photon events. The first part of this project tries to computationally match the experimental results obtained by our collaborators at MIT. Once these results are achieved, …

Magnetic Properties Of Mbe Grown La1/3y1/3sr1/3mno3 Thin Films And Superlattices, W. A. Ruiz, C. Kengle, J. Payne, D. Brown, W. P. Warusawithana, T. M. Pekarek

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

We have investigated the magnetic properties of thin films related to the standard CMR system La2/3Sr1/3MnO3 where Y substituted for 50% of the La atoms. These La1/3Y1/3Sr1/3MnO3 films were grown as a random alloy where La, Y, and Sr atoms randomly occupied the A-site or as a superlattice where each unit-cell-thick layer stacked along the crystallographic (001) direction contained only one of the atoms La, Y, and Sr occupying the A-site. One of the key magnetic features of La2/3Sr1/3MnO3 is a prominent ferromagnetic transition near 350 K. We find the substitution of La with Y suppresses this ferromagnetic transition in …

Spin-Glass Ordering In The Diluted Magnetic Semiconductor Zn1-Xmnxte, S. Barrett, T. M. Pekarek

Showcase of Osprey Advancements in Research and Scholarship (SOARS)

Magnetic measurements on the spin-glass behavior in the bulk II-VI diluted magnetic semiconductor (DMS) ZnMnTe were made on two crystals of concentrations x = 0.43 and 0.55 taken from the same boule. Magnetization and density functional theory studies have shown paramagnetic behavior in both samples between 30 and 400 K. Below 30 K, there is a prominent peak at Tc = 15 and 23.6 K for concentrations x = 0.43 and 0.55, respectively. The splitting of the field cooled (FC) and zero field cooled (ZFC) data below this peak is indicative of a transition to a spin-glass state at low …