Digital Commons Network^™

Cross-Correlation Increases Sampling In Diffusion-Based Super-Resolution Optical Fluctuation Imaging, Jeanpun Antarasen, Benjamin Wellnitz, Stephanie N. Kramer, Surajit Chatterjee, Lydia Kisley

Faculty Scholarship

Correlation signal processing of optical three-dimensional (x, y, t) data can produce super-resolution images. The second-order cross-correlation function XC2 has been documented to produce super-resolution imaging with static and blinking emitters but not for diffusing emitters. Here, we both analytically and numerically demonstrate cross-correlation analysis for diffusing particles. We then expand our fluorescence correlation spectroscopy super-resolution optical fluctuation imaging (fcsSOFI) analysis to use cross-correlation as a postprocessing computational technique to extract both dynamic and structural information on particle diffusion in nanoscale structures simultaneously. Cross-correlation maintains the same super-resolution as auto-correlation while also increasing the sampling rates to reduce aliasing for …

Answers To Frequently Asked Questions About The Pulsar Timing Array Hellings And Downs Curve, Joseph D. Romano, Bruce Allen

Physics & Astronomy Faculty Publications

We answer frequently asked questions (FAQs) about the Hellings and Downs correlation curve—the ‘smoking-gun’ signature that pulsar timing arrays (PTAs) have detected gravitational waves (GWs). Many of these questions arise from inadvertently applying intuition about the effects of GWs on LIGO-like detectors to the case of pulsar timing, where not all of it applies. This is because Earth-based detectors, like LIGO and Virgo, have arms that are short (km scale) compared to the wavelengths of the GWs that they detect (≈102–104 km). In contrast, PTAs respond to GWs whose wavelengths (tens of light-years) are much shorter than their arms (a …

Space Radiation Assessment And Mitigation: Meeting The Growing Demand For Shielding Solutions By Enhancing Models And Exploring Novel Shielding Opportunities, M. Laura Sorgi Johann

Doctoral Dissertations and Master's Theses

The rapid growth of satellite technology and the increasing presence of vulnerable technology and human life in space have highlighted the need for improved shielding materials. Industry standard protocols for shielding are being pushed to their limits as we gain a deeper understanding of the harsh space environment and as chip sizes approach the scale of radiation wavelengths. Furthermore, the commercialization of space is attracting interest from industries such as pharmaceuticals and semiconductor crystal growing, as they explore the potential benefits of zero-gravity production environments. However, the eagerness to develop lighter shielding and the lack of consideration for existing tools …

Electroweak Structure And Reactions In Light Nuclei With Quantum Monte Carlo Methods, Garrett King

Arts & Sciences Graduate Student Theses and Dissertations

Nuclei will play a prominent role in searches for physics beyond the Standard Model as the active material in experiments. In order to reliably interpret new physics signals, one needs an accurate model of the underlying nuclear dynamics. In this thesis, I discuss the validation of the Norfolk two-and three-body model of nuclear interactions along with consistent sets of electroweak transition operators used in conjunction with quantum Monte Carlo approaches to compute electroweak structure and reaction observable in light nuclei. I will provide the salient details of the model and method before presenting calculations of $\beta$-decay rates and spectra, muon …

Freedom As The Physical Notion. Mechanics Of A Material Point, Michael Vigdorowitsch

Karbala International Journal of Modern Science

This is a novel conceptual attempt to introduce freedom as a consistent physical notion. The present consideration is limited to mechanics of a material point. Adapted to physical representation, freedom is tested throughout the paper to conform to its general perception. It is first tried on such physical notions (but not restricted to) as potency of a set, Lagrangian, action, degrees of freedom. Defined as angular and essentially nonlinear variable, it appears to be dual as that the domain affords and that the material point possesses within the domain, not necessarily equal to one another. Freedom has to degrade if …

Glitch Veto Based On Unphysical Gravitational Wave Binary Inspiral Templates, Raghav Girgaonkar, Soumya D. Mohanty

Physics & Astronomy Faculty Publications

Transient signals arising from instrumental or environmental factors, commonly referred to as glitches, constitute the predominant background of false alarms in gravitational wave searches with ground-based detectors. Therefore, effective data analysis methods for vetoing glitch-induced false alarms are crucial to enhancing the sensitivity of a search. We present a veto method for glitches that impact matched filtering-based searches for binary inspiral signals. The veto uses unphysical sectors in the space of chirp time parameters as well as an unphysical extension including negative chirp times to efficiently segregate glitches from gravitational wave signals in data from a single detector. Inhabited predominantly …

Calibrating The Global Network Of Gravitational Wave Observatories Via Laser Power Calibration At Nist And Ptb, Dripta Bhattacharjee, Richard Lenox Savage, Rishabh Bajpai, Joseph Betzwieser, Vladimir Bossilkov, Dan Chen, Cervane Grimaud, Shingo Hido, Sudarshan Karki, Francisco Llamas

Physics & Astronomy Faculty Publications

Current gravitational wave (GW) observatories rely on photon calibrators that use laser radiation pressure to generate displacement fiducials used to calibrate detector output signals. Reducing calibration uncertainty enables optimal extraction of astrophysical information such as source distance and sky position from detected signals. For the ongoing O4 observing run that started on 24 May 2023, the global GW detector network is employing a new calibration scheme with transfer standards calibrated at both the National Institute of Standards and Technology (NIST) and the Physikalisch-Technische Bundesanstalt (PTB). These transfer standards will circulate between the observatories and the metrology institutes to provide laser …

Quantum Classical Algorithm For Solving The Hubbard Model Via Dynamical Mean-Field Theory, Anshumitra Baul

LSU Doctoral Dissertations

Modeling many-body quantum systems is widely regarded as one of the most promising applications for near-term noisy quantum computers. However, in the near term, system size limitation will remain a severe barrier for applications in materials science or strongly correlated systems. A promising avenue of research is to combine many-body physics with machine learning for the classification of distinct phases. I present a workflow that synergizes quantum computing, many-body theory, and quantum machine learning (QML) for studying strongly correlated systems. In particular, it can capture a putative quantum phase transition of the stereotypical strongly correlated system, the Hubbard model. Following …

Inverse-Kinematics Proton Scattering From 42si, Alyssa Himmelreich

Physics and Astronomy Summer Fellows

We studied the neutron-rich isotope ⁴²Si using inverse-kinematics proton scattering from a liquid hydrogen target at the Facility of Rare Isotope Beams at Michigan State University. We utilized a supercomputer to run multiple Geant4 simulations and fit them to our measured gamma-ray spectrum. The simulated spectrum is used to find the energy and half-life of the first excited state. We deduced inelastic-scattering cross-sections using the Gretina gamma-ray tracking array. Our results provide a sensitive test of shell-model descriptions of the evolution of the N=28 shell below ⁴⁸Ca.

Activity: Students Find Conceptual Errors In Ai Output, Janie Brennan

Generative AI Teaching Activities

Instructor asks ChatGPT questions related to a key concept to find one where ChatGPT has conceptual errors. Ask students to find the errors and explain them.

Using Cache Files To Improve The Efficiency Of The Ucgretina Simulation Code, Blake Mcnulty

Physics and Astronomy Summer Fellows

UCGretina is a program that is used to simulate the Gretina gamma-ray tracking array used in experiments at the Facility for Rare Isotope Beams (FRIB) to collect gamma rays produced in reactions such as proton scattering. This is done by generating a simulation of the beam particles used and sending them into a simulated recreation that mimics the experimental environment. My job this summer was to tackle a major issue that the program had which is the speed or efficiency at which it ran. The main issue was that it would take days for certain simulation sets to run which …

Topics In Photonic Quantum Technology: Polarization Entanglement Dynamics In Optical Fibers And Low-Light Imaging., Pratik J. Barge

LSU Doctoral Dissertations

Recent advances in quantum photonics promise transformative impacts on computing, communication, sensing, and imaging. This thesis explores two areas in photonic quantum technology: polarization entanglement dynamics in optical fibers and low-light imaging. Optical fibers are the most suitable medium for photonic qubits and long-distance entanglement distribution is a critical requirement to realize quantum technologies. We study the decay of polarization-entanglement of the Bell state photons propagating through imperfect optical fibers with spatially fluctuating refractive index. Furthermore, to extend the distribution distance, we propose the use of dynamical decoupling in the optical fiber using half waveplates and show that significant improvement …

Exploration Of Semiconductor Gain Medium, Resonator, Pump, And Frequency Stabilization For Laser Guide Star Applications, Mingyang Zhang

Optical Science and Engineering ETDs

Laser Guide Star (LGS) systems are essential for adaptive optics in ground-based astronomical observation. This dissertation demonstrates the feasibility of semiconductor-based LGS systems using the membrane external-cavity surface-emitting laser (MECSEL) platform, employing multiple quantum wells. Various laser cavity configurations were analyzed through simulations and experiments. The in-well pumping method was explored to reduce the quantum defect and address thermal limitations. Multi-pass pumping schemes were designed with Zemax modeling and demonstrated experimentally. To simplify multi-pass pumping, the hybrid-MECSEL (H-MECSEL) design was introduced. COMSOL modeling studied thermal management and thermal lensing effect.

The H-MECSEL achieved approximately 30 W of output power at …

Comparing Thin And Volume Regimes Of Analog Holograms For Wavefront Sensing, Emma Branigan, Andreas Zepp, Suzanne Martin, Matthew Sheehan, Szymon Gladysz, Kevin Murphy

Articles

Two analog holographic wavefront sensors, for measurement of defocus, have been fabricated as both thin and volume phase transmission holograms in a self-developing photopolymer. This represents the first reported direct comparison of hologram regimes when designed for wavefront sensing. An analysis of the effect of crosstalk in the presence of one other aberration mode (astigmatism X (0/90°), coma X (horizontal), and primary spherical aberration) was carried out with each version of the sensor. The performance of thin and volume analog holographic wavefront sensors was characterized under emulated conditions associated with moderate atmospheric turbulence.

Superphenomena For Arbitrary Quantum Observables, Andrew N. Jordan, Yakir Aharonov, Daniele C. Struppa, Fabrizio Colombo, Irene Sabadini, Tomer Shushi, Jeff Tollaksen, John C. Howell, A. Nick Vamivakas

Mathematics, Physics, and Computer Science Faculty Articles and Research

Superoscillations occur when a globally band-limited function locally oscillates faster than its highest Fourier component. We generalize this effect to arbitrary quantum-mechanical operators as a weak value, where the preselected state is a superposition of eigenstates of the operator with eigenvalues bounded to a range, and the postselection state is a local position. Superbehavior of this operator occurs whenever the operator's weak value exceeds its eigenvalue bound. We give illustrative examples of this effect for total angular momentum and energy. In the latter case, we demonstrate a sequence of harmonic oscillator potentials where a finite-energy state converges everywhere on the …

Recoil-Order And Radiative Corrections To The Acorn Experiment, F. E. Wietfeldt, W. A. Byron, B. Collett, M. S. Dewey, T. R. Gentile, F. Glück, M. T. Hassan, G. L. Jones, Alexander Komives, J. S. Nico, E. J. Stephenson

Physics & Astronomy Faculty publications

The aCORN experiment measures the electron-antineutrino correlation 𝑎 coefficient in free neutron decay. We update the previous aCORN results [G. Darius et al., Phys. Rev. Lett. 119, 042502 (2017) and M. T. Hassan et al., Phys. Rev. C 103, 045502 (2021)] to include radiative and recoil corrections to first order, and discuss a key issue in the comparison of results from different 𝑎-coefficient experimental methods when these effects are considered. The corrected combined result is ‾𝑎=−0.10779±0.00125⁢(stat)±0.00134⁢(sys), averaged over the full Fermi neutron beta spectrum. The corresponding corrected result for the ratio of weak coupling constants 𝜆=𝐺𝐴/𝐺𝑉 is …

Design Of Long-Distance Entanglement Distribution Protocols For Quantum Networks, Stav Haldar

LSU Doctoral Dissertations

Future quantum technologies such as quantum communication, quantum sensing, and distributed quantum computation, will rely on networks of shared entanglement between spatially separated nodes. Distributing entanglement between these nodes, especially over long distances, currently remains a challenge, due to limitations resulting from the fragility of quantum systems, such as photon losses, non-ideal measurements, and quantum memories with short coherence times. In the absence of full-scale fault-tolerant quantum error correction, which can in principle overcome these limitations, we should understand the extent to which we can circumvent these limitations. In this work, we provide improved protocols and policies for entanglement distribution …

Generation Of Kochen-Specker Contextual Sets In Higher Dimensions By Dimensional Upscaling Whose Complexity Does Not Scale With Dimension And Their Applications, Mladen Pavičić, Mordecai Waegell

Mathematics, Physics, and Computer Science Faculty Articles and Research

Recently, handling of contextual sets, in particular Kochen-Specker (KS) sets, in higher dimensions has been given an increasing attention, both theoretically and experimentally. However, methods of their generation are diverse, not generally applicable in every dimension, and of exponential complexity. Therefore, we design a dimensional upscaling method, whose complexity does not scale with dimension. As a proof of principle we generate manageable-sized KS master sets in up to 27 dimensional spaces and show that well over 32 dimensions can be reached. From these master sets we obtain an ample number of smaller KS sets. We discuss three kinds of applications …

Strength Measurement Of The E_Α^Lab = 830 Kev Resonance In The Ne 22 ( Α , N ) Mg 25 Reaction Using A Stilbene Detector, Shahina S., R. J. Deboer, J. Gorres, R. Fang, Michael T. Febbraro, R. Kelmar, M. Matney, K. Manukyan, J. T. Nattress, E. Robles, T. J. Rutland, T. T. King, A. Sanchez, R. S. Sidhu, E. Stech, M. Wiescher

Faculty Publications

The interplay between the ²²Ne (��,��)²⁶Mg reaction and the competing ²²Ne(��,��)²⁵Mg reaction determines the efficiency of the latter as a neutron source at the temperatures of stellar helium burning. In both cases, the rates are dominated by the ��-cluster resonance at 830 keV. This resonance plays a particularly important role in determining the strength of the neutron flux for both the weak and main �� process as well as the �� process. Recent experimental studies based on transfer reactions suggest that the neutron and ��-ray strengths for this resonance are approximately equal. In this …

How Are Entanglement Entropies Related To Entropy Bounds?, Emily Adlam

Philosophy Faculty Articles and Research

In this paper we seek to understand what current knowledge of entanglement entropies suggests about the appropriate way to interpret the covariant entropy bound. We first begin by arguing that just as in the classical case, a universal bound on the von Neumann entropy could have either an epistemic or ontological origin. We then consider several possible ways of explaining the bound as a consequence of features of the entanglement entropy. We discuss consider area laws in condensed matter and quantum field theory, arguing that they suggest an epistemic reading of the bound. We also discuss the ‘spacetime from entanglement’ …

The Chemistry Of Heavy Elements: Probing Relativistic Chemical Bonding, Barbara Maria Teixeira Costa Peluzo

Chemistry Theses and Dissertations

The bottommost part of the periodic table has a unique chemistry, where the high velocities of the inner-shell electrons prevent their description by the usual Schrödinger equation. The resulting so-called relativistic effects have numerous chemical implications, on both macro and microscale, ranging from physical properties to reactivity. However, experimental probes on these intriguing atoms are limited by their natural availability and, more importantly, the danger associated with their radioactivity. Quantum chemical calculations, on the other hand, face the challenge of far more complex algebra, which demands substantial computational resources. Relativistic Hamiltonians, which act over all electrons in the system, are …

Laser 3d Printing Of Diamond-Based Composite Materials For Thermal Management Applications, Nada Kraiem

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

With the trend towards miniaturization of electrical equipment and the constant increase in power density in semiconductor devices, efficient heat management has become a major concern for researchers. Indeed, this technological evolution imposes increasingly strict constraints in terms of thermal dissipation, necessitating innovative solutions to ensure better durability and reliability of components. In this context, the use of composite materials offering high thermal conductivity (TC) and low coefficient of thermal expansion (CTE) compared to pure metals has become essential to address overheating issues in electronic components.

The utilization of advanced materials such as diamond (D), with exceptional TC and hardness …

Balloon Borne Gps-Enabled Radiosondes That Enable Simultaneous Multi-Point Atmospheric Sensing With A Single Ground Station, Peter A. Ribbens

Doctoral Dissertations and Master's Theses

Radiosondes are balloon borne atmospheric instruments that are a critical tool for understanding dynamics in the lower layers of the atmosphere. The low-cost radiosondes developed in the Space and Atmospheric Instrumentation Lab have been further developed to improve the system's use as a science-quality atmospheric instrument that is unique in its ability to simultaneously track multiple sondes with a single ground station. Sensors to measure temperature and pressure were added to improve measurements of the atmospheric state. A printed circuit board shield and 3D-printed shell were designed to make mass manufacturing possible. A thermistor-based temperature sensor was developed and tested …

Crosssections, Summer 2024, University Of Northern Iowa. Department Of Physics.

CrossSections

Contents:

A Message from the Department Head, Dr. Paul Shand --- 01
New Secretary --- 02
Homecoming Picnic --- 03
Visits to the Department --- 04
Awards Banquet --- 05
Begeman Lecture --- 05
Physics Competition --- 06
Holiday Colloquium --- 06
Tim Kidd Lecture --- 07
Faculty Profile - Larry Escalada --- 07
Student Profile - Ashley Harrington --- 08
Student Research - Haley Harms --- 10
Physics Scholarships and Awards --- 12
Teacher Education Transformation --- 13
Alumni Profile - Justin Bohnet --- 14
Alumni News - Corey Cooling --- 15
Alumni News - John Bolte --- 16 …

On The Development Of A Software Pipeline For Automatic Detection Of Transients With The Transient Optical Robotic Observatory Of The South, Alejandro Reyes

Theses and Dissertations

The Transient Optical Robotic Observatory of the South (TOROS) telescope has the mission to follow up transient events in the southern hemisphere by surveying the visible sky and responding to detection alerts from space and ground based observatories, such as the Fermi Gamma-Ray Telescope, the Swift X-ray Telescope, and the LIGO VIRGO Kagra gravitational wave detectors. In this work we study the automation of various data analysis pipelines and instrumentation control under development for implementation at the TOROS observatory. I present the design of libraries and routines for data organization, archival, and data reduction, as well as a tool to …

Generating Bessel Beams With An Elastomeric Replica Of A Weevil Carapace, Paz Victoria T. Ramos, Michie Vianca D. De Vera, Raphael Guerrero

Physics Faculty Publications

We generate a zero-order Bessel beam with a laser beam focused onto an elastomeric replica of a weevil carapace scale. Carapace surface structures are imprinted on an elastomeric cast via soft lithography. The output Bessel beam exhibits the expected properties of non-diffraction over a propagation range of 30 cm. The width of the central spot at a propagation distance of 25 cm is 296:8 μm, corresponding to a replicated weevil scale with a diameter of 64.3 μm acting as an annular slit. Self-healing of the beam after encountering a wire obstruction is also observed.

Eighth-Order Foldy-Wouthuysen Transformation, Ulrich D. Jentschura

Physics Faculty Research & Creative Works

The calculation of higher-order binding corrections to bound systems is a fundamental problem of theoretical physics. For any nonrelativistic expansion, one needs the Foldy-Wouthuysen transformation, which disentangles the particle and the antiparticle degrees of freedom. This transformation is carried out here to eighth order in the momenta or to eighth order in the momentum operators, which is equivalent to the eighth order of the fine-structure constant. Matrix elements of the eighth-order terms are evaluated for F_5/2 and F_7/2 states in hydrogenlike ions and compared with the Dirac-Coulomb energy levels.

Accelerating The Efficiency Of Multiscale Hybridizable Discontinuos Galerkin Methods For Flows In Heterogeneous Media, Tony Charles Haines

Mathematics & Statistics Theses & Dissertations

A plethora of scientific and engineering problems encountered are multiscale in nature. This multiscale feature often influences simulation efforts wherever large disparities in spatial scales are experienced. Notable examples include composite materials, fluid flow through porous media and turbulent transport in high Reynolds number flow. Although there are promising results from the advancement of modern supercomputer, obtaining direct numerical solution of multiscale problems is very laborious. This difficulty stems from the tremendous amount of computer memory and CPU time required. Parallel computing may be one obvious choice in remedying this issue. However, the complexity and size of the discrete problem …

Measurement Of The Photoproduction Cross-Section Of F1(1285) In The Exclusive Reactions Γp → P′K∓KSΠ± At 7.5 < Eγ < 11.5 Gev With Gluex At Jefferson Lab, Tyler Viducic

Physics Theses & Dissertations

The f₁(1285) meson is commonly understood to belong to the axial-vector nonet as the low-mass isoscalar partner to the f₁(1420) but has been suggested as a candidate for a KK^∗+c.c molecule. A nearly mass-degenerate 0 ⁻⁺ state has been observed in πp scattering that calls into question the established branching ratios of the f₁(1285) decays. Recently, the differential cross-section for the photoproduction of f₁(1285) was measured by the CLAS experiment and the results disagreed with theoretical predictions. Additionally, the CLAS experiment did not observe a mass-degenerate 0⁻⁺ state. …

Parallel-In-Time Implicit Schemes For Nonlinear Pdes, Subhash Paudel

Mathematics & Statistics Theses & Dissertations

An accurate prediction of unsteady physical phenomena arising in various applications (e.g., rotorcraft and turbomachinery flows, fluid-structure interaction, maneuvering flight conditions, etc.) requires a very large number of time steps, thus considerably increasing the total computational time, because conventional time integrators are inherently sequential. Parallel-in-time methods offer a promising direction for drastically reducing the computational time and achieving such scalability that is required for solving these unsteady problems on modern supercomputers with hundreds of thousands of computing cores. The parallel performance of existing parallel-in-time algorithms for nonlinear equations especially of the hyperbolic or mixed type is far from being satisfactory. …