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Exploring The Localization Of Light In Discrete Systems With Conducted Symmetries, Aria Hajikhani

Theses and Dissertations

Controlling the localization of light has been studied through many approaches and has become a subject matter of interest due to potential applications in various fields. In this thesis, we will explore discrete systems with conducted symmetries, in both quantum and classical aspects, to establish a deeper understanding of light localization. First, we investigate atom-light interactions through exploring the Jaynes-Cummings model. We then introduce coupled cavity arrays (CCAs) where photons can hop between neighboring cavities and each cavity in the array may interact with one or more atoms. Specifically, we focus on systems in which one two-level atom is connected …

Measurement Of The Total Cross-Section Of Muon Neutrino Charged-Current Coherent Pion Production In Nova Near Detector, Kuruppumullage Don Chatura Dilshan Kuruppu

Theses and Dissertations

Charged Current (CC) coherent neutrino-nucleus pion production is characterized by small momentum transferred to the nucleus, which is left in its ground state. Despite the relatively large uncertainties on the production cross-section, coherent production of mesons by neutrinos represents an important process, as it can shed light on the structure of the weak current and can also constitute a potential source of background for modern neutrino oscillation experiments and searches for Beyond Standard Model (BSM) physics. This Ph.D. thesis presents a new measurement of CC coherent pion production in the NOvA near detector at the Fermi National Accelerator Laboratory (Fermilab). …

Yield Extraction For The Γd → Λ X Reaction, K H P Nishadi Hasarangi Silva

Theses and Dissertations

Improving and adding new experimental measurements of hyperon-nucleon (YN) and hyperon-deuteron (Yd) cross sections is an active area in nuclear physics research. Scientists use such cross-section data to understand the composition of neutron stars and develop a comprehensive picture of the baryon-baryon interaction. Using high luminosity photon beam incident on a long liquid deuterium target and the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility (JLab), a sample of hyperon-deuteron elastic scattering events was previously identified. The E06-103 (g13) experiment was originally designed to address the scarcity of experimental data on hyperon photoproduction off the neutron …

Computational Model Of Twisted Elastic Ribbons, Madelyn Leembruggen, Jovana Andrejevic, Arshad Kudrolli, Chris H. Rycroft

Physics

We develop an irregular lattice mass-spring model to simulate and study the deformation modes of a thin elastic ribbon as a function of applied end-to-end twist and tension. Our simulations reproduce all reported experimentally observed modes, including transitions from helicoids to longitudinal wrinkles, creased helicoids and loops with self-contact, and transverse wrinkles to accordion self-folds. Our simulations also show that the twist angles at which the primary longitudinal and transverse wrinkles appear are well described by various analyses of the Föppl-von Kármán equations, but the characteristic wavelength of the longitudinal wrinkles has a more complex relationship to applied tension than …

A Convolutional Neural Network Based Approach To Study The Gravitational Waves From Core-Collapse Supernovae In Ligo's Third Observation Run: Detection Efficiency And Parameter Estimation, Bhawana Sedhai

Theses and Dissertations

Core-Collapse Supernova (CCSN) is one of the most anticipated sources of Gravitational Waves (GW) arriving at the advanced LIGO detectors during the fourth observation run (O4). CCSN are rare, weak and unmodeled having a very low rate of occurrence in our galaxy (estimated 2 per century). Thus, detection of GW from CCSN is a challenging problem. An analysis pipeline used in this study is Multi-Layer Signal Enhancement with cWB and CNN or MuLaSEcC that combines Machine Learning methods with a network of Gravitational Wave detectors to identify and reconstruct signals from core collapse supernovae, while minimizing false alarms through the …

Logarithmic Terms In Atom-Surface Potentials: Limited Applicability Of Rational Approximations For Intermediate Distance, Ulrich D. Jentschura, C. Moore

Physics Faculty Research & Creative Works

It is usually assumed that interaction potentials, in general, and atom-surface potential, in particular, can be expressed in terms of an expansion involving integer powers of the distance between the two interacting objects. Here, we show that, in the short-range expansion of the interaction potential of a neutral atom and a dielectric surface, logarithms of the atom-wall distance appear. These logarithms are accompanied with logarithmic sums over virtual excitations of the atom interacting with the surface in analogy to Bethe logarithms in quantum electrodynamics. We verify the presence of the logarithmic terms in the short-range expansion using a model problem …

Galaxy Clustering In The Mira-Titan Universe. I. Emulators For The Redshift Space Galaxy Correlation Function And Galaxy-Galaxy Lensing, Juliana Kwan, Shun Saito, Alexie Leauthaud, Katrin Heitmann, Salman Habib, Nicholas Frontiere, Hong Guo, Song Huang, Adrian Pope, Sergio Rodriguéz-Torres

Physics Faculty Research & Creative Works

We construct accurate emulators for the projected and redshift space galaxy correlation functions and excess surface density as measured by galaxy-galaxy lensing, based on halo occupation distribution modeling. Using the complete Mira-Titan suite of 111 N-body simulations, our emulators vary over eight cosmological parameters and include the effects of neutrino mass and dynamical dark energy. We demonstrate that our emulators are sufficiently accurate for the analysis of the Baryon Oscillation Spectroscopic Survey DR12 CMASS galaxy sample over the range 0.5 ≤ r ≤ 50 h −1 Mpc. Furthermore, we show that our emulators are capable of recovering unbiased cosmological constraints …

Algebraic Approach To Relativistic Landau Levels In The Symmetric Gauge, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

We use an algebraic approach to the calculation of Landau levels for a uniform magnetic field in the symmetric gauge with a vector potential A→=12(B→xr→), where B→ is assumed to be constant. The magnetron quantum number constitutes the degeneracy index. An overall complex phase of the wave function, given in terms of Laguerre polynomials, is a consequence of the algebraic structure. The relativistic generalization of the treatment leads to fully relativistic bispinor Landau levels in the symmetric gauge, in a representation which writes the relativistic states in terms of their nonrelativistic limit, and an algebraically accessible lower bispinor component. Negative-energy …

Memory-Multi-Fractional Brownian Motion With Continuous Correlations, Wei Wang, Michał Balcerek, Krzysztof Burnecki, Aleksei V. Chechkin, Skirmantas Janušonis, Jakub Ślȩzak, Thomas Vojta, Agnieszka Wyłomańska, Ralf Metzler

Physics Faculty Research & Creative Works

We propose a generalization of the widely used fractional Brownian motion (FBM), memory-multi-FBM (MMFBM), to describe viscoelastic or persistent anomalous diffusion with time-dependent memory exponent α(t) in a changing environment. In MMFBM the built-in, long-range memory is continuously modulated by α(t). We derive the essential statistical properties of MMFBM such as its response function, mean-squared displacement (MSD), autocovariance function, and Gaussian distribution. In contrast to existing forms of FBM with time-varying memory exponents but a reset memory structure, the instantaneous dynamic of MMFBM is influenced by the process history, e.g., we show that after a steplike change of α(t) the …

Crosssections, Summer 2023, University Of Northern Iowa. Department Of Physics.

CrossSections

Contents:

A Message from the Department Head, Dr. Paul Shand --- 1
Department Happenings --- 2
Faculty Profile: Andrew Stollenwerk --- 7
Student Profile: Lukas Stuelke --- 8
Student Focus: Jenna Heinen --- 11
Physics Education --- 13
Alumni Profile: Sam Prophet --- 14
Alumni News: Shawn Poellet --- 15
New Physics: Quantum Mechanics Must Be Complex --- 17

Modified Geometries, Clifford Algebras And Graphs: Their Impact On Discreteness, Locality And Symmetr, Roman Sverdlov

Mathematics & Statistics ETDs

In this dissertation I will explore the question whether various entities commonly used in quantum field theory can be “constructed". In particular, can spacetime be “constructed" out of building blocks, and can Berezin integral be “constructed" in terms of Riemann integrals.

As far as “constructing" spacetime out of building blocks, it has been attempted by multiple scientific communities and various models were proposed. But the common downfall is they break the principles of relativity. I will explore the ways of doing so in such a way that principles of relativity are respected. One of my approaches is to replace points …

Size Effect On The Optical Response Of Cylindrical Palladium Nanoparticles, Salem Marhaba, Mohammed Khalaf

BAU Journal - Science and Technology

In this work, a computational study is carried out to investigate the optical response of palladium nano-cylinders. The Finite Element Method (FEM) is employed using the COMSOL MULTIPHYSICS simulation program to calculate the scattering, absorption, and extinction cross-sections. The influence of the size of the cylindrical nanoparticles on their optical properties is discussed. The results are plotted for a broad spectral range of wavelengths from ultra-violet to infra-red of the incident electromagnetic wave on the cylindrical nanoparticles.

Search For Low-Mass Dark Matter Via Bremsstrahlung Radiation And The Migdal Effect In Supercdms, M. F. Albakry, I. Alkhatib, D. Alonso-González, D. W. P. Amaral, T. Aralis, T. Aramaki, I. J. Arnquist, I. Ataee Langroudy, E. Azadbakht, S. Banik, C. Bathurst, R. Bhattacharyya, P. L. Brink, R. Bunker, B. Cabrera, R. Calkins, R. A. Cameron, C. Cartaro, D. G. Cerdeño, Y. -Y. Chang, M. Chaudhuri, R. Chen, N. Chott, J. Cooley, H. Coombes, J. Corbett, P. Cushman, S. Das, F. De Brienne, M. Rios, S. Dharani, M. L. Di Vacri, M. D. Diamond, M. Elwan, E. Fascione, E. Figueroa-Feliciano, C. W. Fink, K. Fouts, M. Fritts, G. Gerbier, R. Germond, M. Ghaith, S. R. Golwala, J. Hall, N. Hassan, B. A. Hines, Z. Hong, E. W. Hoppe, L. Hsu, M. E. Huber, V. Iyer, D. Jardin, V. K. S. Kashyap, M. H. Kelsey, A. Kubik, N. A. Kurinsky, M. Lee, A. Li, M. Litke, J. Liu, Y. Liu, B. Loer, E. Lopez Asamar, P. Lukens, D. B. Macfarlane, R. Mahapatra, J. S. Mammo, N. Mast, A. J. Mayer, H. Meyer Zu Theenhausen, É. Michaud, E. Michielin, N. Mirabolfathi, B. Mohanty, J. Nelson, H. Neog, V. Novati, J. L. Orrell, M. D. Osborne, S. M. Oser, W. A. Page, L. Pandey, S. Pandey, R. Partridge, D. S. Pedreros, L. Perna, R. Podviianiuk, F. Ponce, S. Poudel, A. Pradeep, M. Pyle, W. Rau, E. Reid, R. Ren, T. Reynolds, A. Roberts, A. E. Robinson, T. Saab, D. Sadek, B. Sadoulet, I. Saikia, J. Sander, A. Sattari, B. Schmidt, R. W. Schnee, S. Scorza, B. Serfass, S. S. Poudel, D. J. Sincavage, P. Sinervo, J. Street, H. Sun, G. D. Terry, F. K. Thasrawala, D. Toback, R. Underwood, S. Verma, A. N. Villano, B. Von Krosigk, S. L. Watkins, O. Wen, Z. Williams, M. J. Wilson, J. Winchell, C. -P. Wu, K. Wykoff, S. Yellin, Betty A. Young, T. C. Yu, B. Zatschler, S. Zatschler, A. Zaytsev, E. Zhang, L. Zheng, A. Zuniga

Physics

We present a new analysis of previously published SuperCDMS data using a profile likelihood framework to search for sub-GeV dark matter (DM) particles through two inelastic scattering channels: bremsstrahlung radiation and the Migdal effect. By considering these possible inelastic scattering channels, experimental sensitivity can be extended to DM masses that are undetectable through the DM-nucleon elastic scattering channel, given the energy threshold of current experiments. We exclude DM masses down to 220  MeV/𝑐² at 2.7×10−30  cm² via the bremsstrahlung channel. The Migdal channel search provides overall considerably more stringent limits and excludes DM masses down to 30  MeV/𝑐 …

Exploring High School Students' Concept Mastery Of Work And Energy Topics: A Quantitative Descriptive Study With Insights For Stem Learning, Maharani Karunia Putri, Parno Parno, Nuril Munfaridah, Marlina Ali

Jurnal Pendidikan Sains

This quantitative descriptive study investigates the concept mastery of work and energy among high school students, specifically focusing on 105 students from the XI MIPA Laboratory UM High School. The research employs a concept mastery test, adapting Bloom's taxonomy indicators from C2 to C6, comprising 15 reasoned multiple-choice questions with a reliability value of 0.704. Student responses, categorized into No Response (NR), No Understanding (NU), Incorrect Understanding (IU), Partial Understanding (PU), and Sound Understanding (SU), reveal a prevalent mastery level in the category of Incorrect Understanding or partial comprehension of misconceptions. Specifically, NR, NU, IU, PU, and SU categories are …

Exploring The Influence Of Online Inquiry Learning With E-Scaffolding Prompting Question On Problem-Solving Skills In The Work And Energy Topic For Islamic Senior High School Students, Arrika Wifqotu Lailin Nafisah, Supriyono Koes Handayanto, Sunaryono Sunaryono, Chokchai Yuenyong

Jurnal Pendidikan Sains

This comprehensive investigation delves into the impact of integrating e-scaffolding prompting questions into online inquiry learning on students' problem-solving skills (PSS). With an explanatory design and a mixed-methods approach, the study focuses on XI-MIPA class students at MAN 1 Kediri City during the academic year 2022-2023. Utilizing meticulously crafted learning instruments, five problem-solving skills questions, and precise interview guidelines, the research employs triangulation through pre-tests, post-tests, and in- depth interviews. Quantitative data undergoes rigorous scrutiny via Analysis of Covariance (ANCOVA). The primary objective is to unveil the discernible influence of online inquiry learning complemented by e-scaffolding on the nuanced domain …

Study Of Scientific Reasoning And Concept Mastery Of Students Through Guided Inquiry Learning Model Assisted By Formative Assessment, Selvina Visbad Saiya, Sentot Kusairi, Sunaryono Sunaryono

Jurnal Pendidikan Sains

This study endeavors to assess the impact of guided inquiry learning, complemented by formative assessment, on students’ scientific reasoning (SR) and concept mastery (CM). The research involved 20 students from class XI A at SMA Muhammadiyah 02 Sumberpucung, utilizing questions adapted from the modified Lawson classroom test of scientific reasoning (MLCTSR) to measure SR, and the force concept inventory (FCI) to gauge CM. The instructional focus was Newton’s law of motion. Both qualitative and quantitative analyses were employed for data interpretation. The findings revealed a substantial influence of the guided inquiry learning model on SR, with a d-effect size value …

The Effect Of Online Discovery-Inquiry Learning On Improving Critical Thinking Ability And Concept Mastery In Temperature And Heat Materials, Fildzah Purvita Dewi, Lia Yuliati, Edi Supriana

Jurnal Pendidikan Sains

The research endeavors to investigate the impact of implementing discovery-inquiry learning concerning the topic of temperature and heat on the enhancement of students’ critical thinking abilities and concept mastery. The study adopted a quasi-experimental design, employing a pretest-posttest control group framework. A cluster random sampling technique was applied to select the research sample, which comprised 36 students from class XI MIPA 3 (control group) and class XI MIPA 4 (experimental group) at SMA Negeri Rambipuji. The assessment instruments employed were two essay-shaped tests, specifically designed for evaluating critical thinking ability and concept mastery. Data analysis involved the utilization of independent …

Utilization Of Palm Waste Charcoal Briquettes (Abls) As Thematic-Based Integrated Science Learning Materials For Middle School Students, Sausan Fatin Nurazizah, Rendy Wikrama Wardana, Bhakti Karyadi, Henny Johan, Deni Parlindungan, Fitri Mulyani, Lasriani Lasriani

Jurnal Pendidikan Sains

This investigation was conducted with the objective of evaluating the efficacy of ABLS ignition and formulating instructional materials for junior high school science education through the integration of e-booklets containing thematic-based science content. The research design employed herein adheres to the principles of experimentation and model development, falling under the category of Research and Development (R&D). The experimental cohort was stratified into three groups denoted as A1 (70% shell charcoal: 30% bunch charcoal), A2 (50% shell charcoal: 50% bunch charcoal), and A3 (30% shell charcoal: 70% bunch charcoal). The development of science learning materials was realized through integration with cobwebs, …

Thermal Performance Of A Mechanical Thermostat For Charging An Energy Storage System, Swaleh Tusiime, Karidewa Nyeinga, Denis Okello, Ole J. Nydal

Tanzania Journal of Science

Thermal energy storage (TES) systems enhance the use of solar energy for cooking by matching the energy demand to its supply. Useful energy is extracted from TES systems that are thermally stratified and this is enhanced when charged at an averagely constant-temperature. This paper presents an experimental analysis of a mechanical-thermostat used to control the charging of an oil based TES system. The thermostat consisted of a slider-valve, an expansion-system acting both as a thermal-sensor and actuator, and an adjusting-knob for setting the charging temperature. Oil from a cold-oil reservoir flows by gravity into a heating-chamber when a manual valve …

Adaptive Plasmonic Metasurfaces For Radiative Cooling And Passive Thermoregulation, Azadeh Didari-Bader, Nooshin M. Estakhri, Nasim Mohammadi Estrakhri

Engineering Faculty Articles and Research

In this work, we investigate a class of planar photonic structures operating as passive thermoregulators. The radiative cooling process is adjusted through the incorporation of a phase change material (Vanadium Dioxide, VO₂) in conjunction with a layer of transparent conductive oxide (Aluminum-doped Zinc Oxide, AZO). VO₂ is known to undergo a phase transition from the “dielectric” phase to the “plasmonic” or “metallic” phase at a critical temperature close to 68°C. In addition, AZO shows plasmonic properties at the long-wave infrared spectrum, which, combined with VO₂, provides a rich platform to achieve low reflections across the …

Climate Of A Cave Laboratory Representative For Rock Art Caves In The Vézère Area (South-West France), Delphine Lacanette, Léna Bassel, Fabien Salmon, Jean-Christophe Portais, Bruno Bousquet, Rémy Chapoulie, Faten Ammari, Philippe Malaurent, Catherine Ferrier

International Journal of Speleology

Leye Cave (Dordogne, France) is a laboratory cave in the Vézère area, a region that contains some of the most famous rock art caves in the world such as Lascaux, Font-de-Gaume and Combarelles, and is listed as Human World Heritage by UNESCO. Leye Cave was selected because it is representative of painted caves, with respect to parameters such as its geological stage, the presence of water and carbon dioxide, the geological state of its walls, and the size of the cave. These wall states are studied to better understand the conditions of conservation of rock art caves without damaging them. …

Fractional Charge Concept Opened Gates For New Ideas On Composition Of Matter, Polievkt Perov

College of Arts & Sciences Faculty Works

Before the concept of quarks with fractional electric charges was introduced, the electron charge magnitude e was considered as the smallest amount of charge in nature so the charge of any object could be only an integer number of ± e. Then it was suggested that the proton and neutrons are composed of quarks with the fractional charges, combined in such a way that the total charge of a proton occurred to be that same known charge +e, and the charge of a neutron was zero. We suggest expanding that fruitful concept of fractional charges to build structural models of …

The Nanograv 15yr Data Set: Search For Signals From New Physics, Adeela Afzal, Gabriella Agazie, Akash Anumarlapudi, Anne M. Archibald, Zaven Arzoumanian, Paul T. Baker, Bence Bécsy, Jose Juan Blanco-Pillado, Laura Blecha, Kimberly K. Boddy, Adam Brazier, Paul R. Brook, Sarah Burke-Spolaor, Rand Burnette, Robin Case, Maria Charisi, Shami Chatterjee, Katerina Chatziioannou, Belinda D. Cheeseboro, Siyuan Chen, Tyler Cohen, James M. Cordes

Pacific Faculty Work

The 15 yr pulsar timing data set collected by the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) shows positive evidence for the presence of a low-frequency gravitational-wave (GW) background. In this paper, we investigate potential cosmological interpretations of this signal, specifically cosmic inflation, scalar-induced GWs, first-order phase transitions, cosmic strings, and domain walls. We find that, with the exception of stable cosmic strings of field theory origin, all these models can reproduce the observed signal. When compared to the standard interpretation in terms of inspiraling supermassive black hole binaries (SMBHBs), many cosmological models seem to provide a better fit …

An Updated Dust-To-Star Geometry: Dust Attenuation Does Not Depend On Inclination In 1.3 ≤Z ≤2.6 Star-Forming Galaxies From Mosdef, Brian Lorenz, Mariska Kriek, Alice E. Shapley, Naveen A. Reddy, Ryan L. Sanders, Guillermo Barro, Alison L. Coil, Bahram Mobasher, Sedona H. Price, Jordan N. Runco, Irene Shivaei, Brian Siana, Daniel R. Weisz

Pacific Faculty Work

We investigate dust attenuation and its dependence on viewing angle for 308 star-forming galaxies at 1.3 ≤ z ≤ 2.6 from the MOSFIRE Deep Evolution Field survey. We divide galaxies with a detected Hα emission line and coverage of Hβ into eight groups by stellar mass, star formation rate (SFR), and inclination (i.e., axis ratio), and we then stack their spectra. From each stack, we measure the Balmer decrement and gas-phase metallicity, and then we compute the median A V and UV continuum spectral slope (β). First, we find that none of the dust properties (Balmer decrement, A V, or …

New Reaction Of Neutron-Proton Conversion, Polievkt Perov

College of Arts & Sciences Faculty Works

Using our models of composite particles as consisting just of two types of elementary basic charges, +e/3 and -e/3, we suggest that in any nuclear reaction the total numbers of basic charges of each of the two types are conserved. That means that in any nuclear reaction, the basic elementary charges present in the reactants can join in different combinations to form the products of the reaction. This is like a balanced chemical equation where the number of atoms of each element is conserved. We apply this suggested principle of conservation of basic elementary charges in any nuclear reaction to …

Quantum Hamilton–Jacobi Quantization And Shape Invariance, Rathi Dasgupta, Asim Gangopadhyaya

Physics: Faculty Publications and Other Works

Quantum Hamilton-Jacobi quantization scheme uses the singularity structure of the potential of a quantum mechanical system to generate its eigenspectrum and eigenfunctions, and its efficacy has been demonstrated for several well known conventional potentials. Using a recent work in supersymmetric quantum mechanics, we prove that the additive shape invariance of all conventional potentials and unbroken supersymmetry are sufficient conditions for their solvability within the quantum Hamilton-Jacobi formalism.

Intrinsic Point Defects (Vacancies And Antisites) In Cdgep2 Crystals, Timothy D. Gustafson, Nancy C. Giles, Peter G. Schunemann, Kevin T. Zawilski, Kent L. Averett, Jonathan E. Slagle, Larry E. Halliburton

Faculty Publications

Cadmium germanium diphosphide (CdGeP₂) crystals, with versatile terahertz-generating properties, belong to the chalcopyrite family of nonlinear optical materials. Other widely investigated members of this family are ZnGeP₂ and CdSiP₂. The room-temperature absorption edge of CdGeP₂ is near 1.72 eV (720 nm). Cadmium vacancies, phosphorous vacancies, and germanium-on-cadmium antisites are present in as-grown CdGeP₂ crystals. These unintentional intrinsic point defects are best studied below room temperature with electron paramagnetic resonance (EPR) and optical absorption. Prior to exposure to light, the defects are in charge states that have no unpaired spins. Illuminating a CdGeP_{2 …}

Adaptive Quantum Information Processing In Non-Equilibrium Environments, Arshag Danageozian

LSU Doctoral Dissertations

Solid state and condensed matter systems, such as diamond impurities, superconductors, quantum dots, and ion traps, constitute important physical platforms for various applications in quantum information processing (QIP). However, it has consistently been shown that all such modern platforms suffer from non-equilibrium behavior on timescales that are relevant for many important QIP tasks. The causes range from intrinsic non-equilibrium dynamics (e.g. in diamond) to the presence of various impurities with their own internal dynamics (e.g. in superconductors and quantum dots) or variations in the control fields used to stabilize the quantum matter (e.g. in ion traps). When reserving degrees of …

Phase Transitions And Magnetocaloric Effects In Metastable Phases Of Intermetallic Compounds, Tej Bahadur Poudel Chhetri

LSU Doctoral Dissertations

The interplay between spin and lattice degrees of freedom in magnetic materials often results in interesting magnetoresponsive effects. The magnetocaloric effect is one such magnetothermal phenomenon that may be utilized in energy-efficient magnetic cooling systems. This effect becomes more prominent near a coupling of magnetic and structural transitions, i.e., magnetostructural transitions (MSTs). This dissertation investigates phase transitions (magnetic and structural) in metastable phases of MnNiGe- and MnCoGe-based compounds generated through high-pressure synthesis/annealing and thermal quenching techniques and assesses their magnetocaloric effects.

First, the effects of doping, hydrostatic pressure, and thermal quenching on phase transitions and related magnetocaloric effects in Mn …

Optical Response Of 3d Model Topological Nodal-Line Semimetal, Sita Kandel, Godfrey Gumbs, Oleg L. Berman

Publications and Research

Wepresent a semi-analytical expression for both longitudinal and transverse optical conductivities of a model TNLSM employing the Kubo formula with emphasis on the optical spectral weight redistribution, deduced from appropriate Green’s func tions. In this semimetal, the conduction and valence bands cross each other along a one- dimensional curve protected by certain symmetry group in the 3D Brillouin zone. Although the crossing cannot be removed by any perturbations, it can be adjusted by continuous tuning of the Hamiltonian with a parameter α. When α>0, the two bands cross each other near the Γ point in the (kx,ky) plane of …