Physics Commons^™

Novel Photonic Resonance Arrangements Using Non-Hermitian Exceptional Points, Hossein Hodaei

Electronic Theses and Dissertations

In recent years, non-Hermitian degeneracies also known as exceptional points (EPs) have emerged as a new paradigm for engineering the response of optical systems. EPs can appear in a wide class of open non-Hermitian configurations. Among different types of non-conservative photonic systems, parity-time (PT) symmetric arrangements are of particular interest since they provide an excellent platform to explore the physics of exceptional points. In this work, the intriguing properties of exceptional points are utilized to address two of the long standing challenges in the field of integrated photonics- enforcing single mode lasing in intrinsically multimode cavities and enhancing the sensitivity …

Generation Of High-Flux Attosecond Pulses And Towards Attosecond-Attosecond Pump-Probe Experiments, Yang Wang

Electronic Theses and Dissertations

At present, the energy of a single isolated attosecond pulse is limited to nanojoule levels. As a result, an intense femtosecond pulse has always been used in combination with a weak attosecond pulse in time-resolved experiments. To reach the goal of conducting true attosecond pump-attosecond probe experiments, a high flux laser source has been developed that can potentially deliver microjoule level isolated attosecond pulses in the 50 eV range, and a unique experimental end station has been fabricated and implemented that can provide precision control of the attosecond-attosecond pump-probe pulses. In order to scale up the attosecond flux, a unique …

Saving The Physics Ii: Who Needs To Be Saved? It Depends On Your Metaphysics, Menas Kafatos

Mathematics, Physics, and Computer Science Faculty Articles and Research

Physics does not need to be saved. If anything, physics was rescued in the early twentieth century with the advancement of both the theories of relativity and quantum mechanics. What needs to be saved is our world outlook or metaphysics because how a society acts and develops depends on what its belief systems are. Here we explore how a new metaphysics where consciousness is fundamental might just be what modern societies need.

Gamifying Quantum Theory, Matthew S. Leifer

Mathematics, Physics, and Computer Science Faculty Articles and Research

"Over the past few years, the trend of gamification has gradually seeped into quantum research, education and outreach, so that we now have a critical mass of games based on quantum mechanics. I thought the time was right to discuss quantum gamification at the APS March meeting[.]"

Review Of Qbism: The Future Of Quantum Physics, Matthew S. Leifer

Mathematics, Physics, and Computer Science Faculty Articles and Research

A review of QBism: The Future of Quantum Physics by Hans Christian von Baeyer.

Measurement Of Two-Photon Exchange Effect By Comparing Elastic E ± P Cross Sections, D. Rimal, D. Adikaram, B. A. Raue, L. B. Weinstein, J. Arrington, W. K. Brooks, M. Ungaro, K. P. Adhikari, A. V. Afanasev, Z. Akbar

Physics Faculty Publications

Background: The electromagnetic form factors of the proton measured by unpolarized and polarized electron scattering experiments show a significant disagreement that grows with the squared four-momentum transfer (Q²) . Calculations have shown that the two measurements can be largely reconciled by accounting for the contributions of two-photon exchange (TPE). TPE effects are not typically included in the standard set of radiative corrections since theoretical calculations of the TPE effects are highly model dependent, and, until recently, no direct evidence of significant TPE effects has been observed.

Purpose: We measured the ratio of positron-proton to electron-proton elastic-scattering cross …

Status Of The Bonus12 Radial Time Projection Chamber, Gabriel Charles, Stephen Bueltmann, Gail Dodge, Nathan Dzbenski, Mathieu Ehrhardt, Sebastian E. Kuhn, David Payette, Jiwan Poudel, Keith A. Griffioen, Pascal Baron, Irakli Mandjavidze, Eric Christy, I. Hakki Albayrak, Aruni Nadeeshani, Howard Fenker, Narbe Kalantarians, Jixie Zhang, Carlos Ayerbe Gayoso

Physics Faculty Publications

Part of the experimental program in Hall B of the Jefferson Lab, Virginia, USA is dedicated to studying neutron structure functions using deep inelastic scattering on nuclei. For this purpose, the BONuS12 experiment will detect low momentum recoil protons in coincidence with scattered electrons. The protons will be detected by a second-generation Radial Time Projection Chamber (RTPC) using triple Gas Electron Multiplier foils for amplification while the scattered electrons will be detected by the CLAS12 spectrometer installed in Hall B. The following article presents the status of the BONuS12 RTPC detector that will take data within the next 2 years. …

Exploiting Modern Image Processing In Surface Flow Visualisation, Tarek Ihab Abdelsalam, Richard Williams, Grant Ingram

Mechanical Engineering

Surface flow visualisation is an experimental technique where the surface of interest is painted with an oil and dye mixture before a flow is applied to the object. In regions of high shear stress the oil/dye mixture is then removed and in regions of low shear stress the oil/dye mixture stays or builds up. The resulting pattern can be analysed to determine the structure near the surface under test, this is normally done in a qualitative manner with flow structures being identified based on the expertise of the experimentalist. Modern image processing tools can identify shapes and lines in pictures …

Theoretical Study Of Negative Molecular Ions Relevant To The Interstellar And Laboratory Plasma, Marjan Khamesian

Electronic Theses and Dissertations

Recently, several negative molecular ions, CnN- (n = 1, 3, 5) and CnH- (n = 4, 6, 8), were observed in the interstellar medium (ISM). It was suggested that the anions are formed in the ISM by the process of radiative electron attachment (REA). A simple statistical model was developed in 1980's to estimate rate coefficients of the REA reactions. Some of the rate coefficients obtained in the model are consistent with the observations, the others are not. More importantly, some of the approximations employed in the model are not physically justified. The aim of this thesis is a development …

Solving Constraint Satisfaction Problems With Matrix Product States, Sabine Pelton

Electronic Theses and Dissertations

In the past decade, Matrix Product State (MPS) algorithms have emerged as an efficient method of modeling some many-body quantum spin systems. Since spin system Hamiltonians can be considered constraint satisfaction problems (CSPs), it follows that MPS should provide a versatile framework for studying a variety of general CSPs. In this thesis, we apply MPS to two types of CSP. First, use MPS to simulate adiabatic quantum computation (AQC), where the target Hamiltonians are instances of a fully connected, random Ising spin glass. Results of the simulations help shed light on why AQC fails for some optimization problems. We then …

Linking Atr-Ftir And Raman Features To Phenolic Extractability And Other Attributes In Grape Skin, Hugh Byrne, Abigail Rooney, Julio Nogales-Bueno, Jose Miguel Hernandez-Hierro, Francisco Jose Heredia

Articles

The importance of wine phenolics on the sensory characteristic of red wines is well-known. Therefore, it is necessary to control the extractability of phenolic compounds from grape skins, which depends significantly on grape ripeness and hence, on cell wall degradation.

In the present study, attenuated total reflectance Fourier transform infrared (ATR-FTIR) and Raman spectra of grape skin have been recorded. Then, these spectral matrices have been studied and the main spectral features have been linked to extractabilities of phenolic compounds (anthocyanins, flavanols and total phenols). Moreover, spectral differences between external and internal grape skin surfaces also have been studied.

It …

Monitoring Doxorubicin Cellular Uptake And Trafficking Using In Vitro Raman Microspectroscopy: Short And Long Time Exposure Effects On Lung Cancer Cell Lines, Zeineb Farhane, Franck Bonnier, Hugh Byrne

Articles

Raman microspectroscopy is a non-invasive, in vitro analytical tool which is being increasingly explored for its potential in clinical applications and monitoring the uptake, mechanism of action and cellular interaction at a molecular level of chemotherapeutic drugs, ultimately as a potential label-free preclinical screening and companion diagnostic tool. In this study, doxorubicin (DOX), a “gold standard” chemotherapeutic drug, is employed as a model in the in vitro lung cancer cell line A549 in order to demonstrate the potential of Raman microspectroscopy to screen and identify spectroscopic markers of its trafficking and mechanism of action. Confocal laser scanning microscopy (CLSM) was …

A Natural, Calcium-Rich Marine Multi-Material Complex Preserves Bone Structure, Composition And Strength In An Ovariectomized Rat Model Of Osteoporosis, Orlaith Brennan, Joseph Sweeney, Brian O'Meara, Amro Widaa, Franck Bonnier, Hugh Byrne, Denis O'Gorman, Fergal O'Brien

Articles

Calcium supplements are used as an aid in the prevention of osteopenia and osteoporosis and also for the treatment of patients when used along with medication. Many of these supplements are calcium carbonate based. This study compared a calcium-rich, marine multi-mineral complex (Aquamin) to calcium carbonate in an ovariectomised rat model of osteoporosis in order to assess Aquamin’s efficacy in preventing the onset of bone loss. Animals were randomly assigned to either non-ovariectomy control (Control), ovariectomy (OVX) plus calcium carbonate, ovariectomy plus Aquamin or ovariectomy plus Aquamin delay where Aquamin treatment started 8 weeks post OVX. At the end of …

Magnetic Behavior Of Bulk And Nanostructured Mnxtas2, Lucas Paul Beving

Honors Program Theses

At its base, material science research aims to categorize specific materials by their various attributes, such as structure, integrity, electronic properties, magnetic properties, and others. By categorizing materials in this way, it becomes easier to generalize the application of a specific material to those within a broader category. The interest in materials that exhibit useful characteristics at small scales derives directly from the technology industry’s need for smaller and smaller devices. Two-dimensional materials are of great interest for this reason.

Two-dimensional materials are comprised of many single layers, or planes, stacked together to create a crystal. Each layer may be …

On Slowly Rotating Supercompact Schwarzschild Stars, Nelson Camilo Posada-Aguirre

Theses and Dissertations

In this Ph.D thesis, I will present results concerning to my doctoral research project submitted to the Department of Physics and Astronomy at the University of South Carolina. The thesis belongs to the area of Theoretical Physics, particularly, in the framework of Einstein’s Theory of General Relativity.

The project is the study of integral and surface properties of slowly rotating homogeneous masses in the gravastar limit R ! Rs, where Rs is the Schwarzschild radius. For this purpose we followed the perturbative method proposed by Hartle in 1967. In this model, the relativistic equations of structure for a slowly rotating …

Geometric Influence On Electronic Properties: Graphene With Antidots, Two-Dimensional Electron Gas And Three-Dimensional Carbon Nanostructures, Lei Wang

Theses and Dissertations

Geometric influence on electrical and magneto transport properties has been investigated in three types of systems: (i) Graphene, a single layer of carbon atoms; (ii) Two-dimensional electron gas (2DEG) in AlInN/GaN heterostructure; and (iii) 3D carbon nanostructures, a special type of three-dimensional materials with spherical voids. Due to unique structures and energy dispersion relations, these three systems demonstrate distinct physical properties.

AlInN is the newest and amongst the widest band gap semiconductors. The 2DEG in AlInN/GaN heterostucture displays long transport lifetime along with conventional behaviors, including Shubnikov-de Haas (SdH) oscillation and weak localization. From SdH oscillation, the effective mass of …

Determination Of Polarization Transfer Coefficients And Hyperon Induced Polarization For Quasi–Free Hyperon Photoproduction Off The Bound Neutron, Colin Gleason

Theses and Dissertations

The spectrum of the excited nucleon (N*) states provides key information on the relevant degrees of freedom within the nucleon. The determination of the N* spectrum requires an extensive set of high–quality experimental observables for a large number of nuclear reactions over a broad kinematic range. In particular, measurements of polarization observables of strangeness photoproduction are of high importance as many of the resonances that are predicted by quark models, but not observed in pion– nucleon channels, are expected to couple strongly to kaon–hyperon (KY) channels. While in the last decade a large body of polarization and cross–section data has …

Polarization Observables T And F In The Yp -> Pi P Reaction, Hao Jiang

Theses and Dissertations

The theory that describes the interaction of quarks is Quantum Chromodynamics (QCD), but how quarks are bound inside a nucleon is not yet well understood. Pion photoproduction experiments reveal important information about the nucleon excited states and the dynamics of the quarks within it and thus provide a useful tool to study QCD. Detailed information about this reaction can be obtained in experiments that utilize polarized photon beams and polarized targets.

Pion photoproduction in the yp -> pi p reaction has been measured in the FROST experiment at the Thomas Jefferson National Accelerator Facility. In this experiment circularly polarized photons …

Deformation But Not Migration And Rotation – A Model Study On Vesicle Biomechanics In A Uniform Dc Electric Field, Hui Ye, Austen Curcuru

Biology: Faculty Publications and Other Works

Background: Biological cells migrate, deform and rotate in various types of electric fields, which have significant impact on the normal cellular physiology. To investigate electrically-induced deformation, researchers have used artificial giant vesicles that mimic the phospholipid bilayer cell membrane. Containing primarily the neutral molecule phosphatidylcholine, these vesicles deformed under evenly distributed, strong direct current (DC) electric fields. Interestingly, they did not migrate or rotate. A biophysical mechanism underlying the kinematic differences between the biological cells and the vesicles under electric stimulation has not been worked out.

Methods: We modeled the vesicle as a leaky, dielectric sphere and computed …

The Intrinsic Variability Of The Water Vapor Saturation Ratio Due To Mixing, Jesse Anderson

Dissertations, Master's Theses and Master's Reports

The water vapor concentration plays an important role for many atmospheric processes. The mean concentration is key to understand water vapor's effect on the climate as a greenhouse gas. The fluctuations about the mean are important to understand heat fluxes between Earth's surface and the boundary layer. These fluctuations are linked to turbulence that is present in the boundary layer. Turbulent conditions are simulated in Michigan Tech’s multiphase, turbulent reaction chamber, the π chamber. Measurements for temperature and water vapor concentration were recorded under forced Rayleigh- Bénard convection at several turbulent intensities. These were used to calculate the saturation ratio, …

Quantum Inspired Symmetries In Laser Engineering, Mohammad Hosain Teimourpour

Dissertations, Master's Theses and Master's Reports

In this thesis, quantum inspired symmetries including Parity-Time (PT) symmetry and Supersymmetry (SUSY) have been studied in the context of non-Hermitian engineered laser systems. This thesis starts with a short review of semiconductor lasers theory in second chapter, followed by an introduction to quantum inspired symmetries: PT symmetry and SUSY in optics and photonics in chapter three.

In chapter four, we have studied the robustness and mode selectivity in PT symmetric lasers. We investigate two important aspects of PT symmetric photonic molecule lasers, namely the robustness of their single longitudinal mode operation against instabilities triggered by spectral hole burning effects, …

Non-Hermiticity-Induced Flat Band, Hamidreza Ramezani

Physics & Astronomy Faculty Publications

We demonstrate the emergence of an entire flat band with no complex component embedded in dispersive bands at the exceptional point of a PT -symmetric photonic lattice. For this to occur, the gain and loss parameter effectively alters the size of the partial flat band windows and band gap of the photonic lattice simultaneously. The mode associated with the entire flat band is robust against changes in the system size and survives even at the edge of the lattice. Our proposal offers a route for controllable localization of light in non-Hermitian systems and a technique for measuring non-Hermiticity via localization.

Designer Metasurfaces For On Demand Optical Responses, Matthew S. Lepain

College of Graduate Studies: Theses & Dissertations

Nanostructured materials are one of the leading areas in photonics currently. These structures offer almost limitless possibilities in the manipulation of light. Using two different semi-analytical simulation methods, I show a few of the possible properties that these nanostructures possess, including polarization rotation and coupling with electronics.