Digital Commons Network^™

Aspects Of The Equivalence Between The FΜ And C Vμ Terms In Lorentz-Violating Quantum Field Theory, Sapan Karki, Brett David Altschul

Faculty Publications

It is known that in Lorentz-violating effective field theory, there is a classical equivalence between certain coefficients (c and f), in spite of the fact that the operators of the two types of coefficients described appear to have opposite behaviors under CPT. This paper is a continuation of previous work extending this equivalence to the quantum level: generalizing the explicit spinorial point transformations that interconvert the c and f terms; demonstrating that the transformations do not give rise to any additional anomaly terms as the quantum level; and giving explicit prescriptions for modifying the C, P, and T operators in …

Photoionization Energetics And Dissociation Pathways Of Hydroperoxyethyl Formate Produced In The Reaction Of Ch3Choo + Formic Acid, Vincent J. Esposito, Trent A. Mchenry, Marsha I. Lester

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The bimolecular reaction of Criegee intermediates, zwitterionic carbonyl oxide species produced in alkene ozonolysis, with organic acids leads to formation of functional hydroperoxides implicated in the generation of atmospheric aerosols. This theoretical study using high-level explicitly correlated coupled-cluster theory examines the low energy conformers of hydroperoxyethyl formate [HOOCH(CH₃)OCHO, HPEF] formed in the bimolecular reaction of CH₃CHOO, a simple alkyl-substituted Criegee intermediate, with formic acid, and the detection of HPEF via photoionization. The vertical and adiabatic ionization energies of HPEF are computed, along with the pathways for dissociative ionization that produce HO₂ or OCHO fragments with …

Newtonian Fractional-Dimension Gravity And The External Field Effect, Gabriele Varieschi

Physics Faculty Works

We expand our analysis of Newtonian Fractional-Dimension Gravity (NFDG), an extension of the classical laws of Newtonian gravity to lower dimensional spaces, including those with fractional (i.e., non-integer) dimension. We apply our model to four rotationally supported galaxies (NGC 5033, NGC 6674, NGC 5055, NGC 1090), in addition to other three galaxies (NGC 7814, NGC 6503, NGC 3741) which were analyzed in previous studies. NFDG is able to fit the rotation curves of all these galaxies without any dark matter component. We also investigate the possible violation of the strong equivalence principle, in relation to the External Field Effect (EFE), …

Compilation Optimizations To Enhance Resilience Of Big Data Programs And Quantum Processors, Travis D. Lecompte

LSU Doctoral Dissertations

Modern computers can experience a variety of transient errors due to the surrounding environment, known as soft faults. Although the frequency of these faults is low enough to not be noticeable on personal computers, they become a considerable concern during large-scale distributed computations or systems in more vulnerable environments like satellites. These faults occur as a bit flip of some value in a register, operation, or memory during execution. They surface as either program crashes, hangs, or silent data corruption (SDC), each of which can waste time, money, and resources. Hardware methods, such as shielding or error correcting memory (ECM), …

Sers Platform For Single Fiber Endoscopic Probes, Debsmita Biswas

LSU Doctoral Dissertations

Molecular detection techniques have huge potential in clinical environments. In addition to many other molecular detection techniques, endoscopic Raman spectroscopy has great ability in terms of minimal invasiveness and real-time spectra acquisition. However, Raman Effect is low in sensitivity, limiting the application. Surface-Enhanced Raman Scattering (SERS), addresses this limitation. SERS brings rough nano-metallic surfaces in contact with specimen molecules which enormously enhances Raman signals. This provides Raman spectroscopy with immense capabilities for diverse fields of applications.

Generally, in clinical probe applications, the spectrometer is brought near the target molecules for detection. Typically, optical fibers are used to couple spectrometers to …

Searches For Ultra-High-Energy Photons At The Pierre Auger Observatory, The Pierre Auger Collaboration, B. Fick, D. Nitz, I. Norwood, A. Puyleart, Et Al.

Michigan Tech Publications, Part 1

No abstract provided.

An Interactive Simulation And Visualization Tool For Conventional And Aberration-Corrected Transmission Electron Microscopy, Xingzhong Li

Nebraska Center for Materials and Nanoscience: Faculty Publications

Contrast transfer function (CTF) is a vital function in transmission electron microscopy (TEM). It expresses to what extent amplitudes converted from the phase changes of the diffracted waves contribute to the TEM image, including the effects of lens aberrations. Simulation is very helpful to understand the application of the function thoroughly. In this work, we develop the CTFscope as a component in the Landyne software suite, to calculate the CTF with temporal and spatial dumping envelopes for conventional TEM and to extend it to various aberrations (up to fifth order) for aberration-corrected (AC)- TEM. It also includes effects on the …

Validation Of Standardized Data Formats And Tools For Ground-Level Particle-Based Gamma-Ray Observatories, A. Albert, R. Alfaro, J. C. Arteaga-Velázquez, H. A. Ayala Solares, R. Babu, E. Belmont-Moreno, C. Brisbois, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, O. Chaparro-Amaro, U. Cotti, J. Cotzomi, S. Coutiño De León, E. De La Fuente, R. Diaz Hernandez, M. A. Duvernois, M. Durocher, C. Espinoza, K. L. Fan, M. Fernandez Alonso, N. Fraija, J. A. Garcia-Gonzalez, H. Goksu, M. M. Gonzalez, J. A. Goodman, J. P. Harding, J. Hinton, D. Huang, F. Hueyotl-Zahuantitla, P. Huntemeyer, A. Jardin-Blicq, V. Joshi, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, V. Marandon, O. Martinez, J. Martinez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Morales-Soto, E. Moreno, M. Mostafa, A. Nayerhoda, L. Nellen, M. U. Nisa, R. Noriega-Papaqui, L. Olivera-Nieto, E. G. Perez-Perez, C. D. Rho, D. Rosa-Gonzalez, E. Ruiz-Velasco, D. Salazar-Gallegos, F. Salesa Greus, A. Sandoval, H. Schoorlemmer, J. Serna-Franco, A. J. Smith, Y. Son, R. W. Springer, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Urena-Mena, L. Villasenor, Xiaojie Wang, I. J. Watson, E. Willox, H. Zhou, C. De Leon, A. Zepeda, A. Donath, S. Funk

Physics Faculty Research & Creative Works

Context. Ground-based γ-ray astronomy is still a rather young field of research, with strong historical connections to particle physics. This is why most observations are conducted by experiments with proprietary data and analysis software, as is usual in the particle physics field. However, in recent years, this paradigm has been slowly shifting toward the development and use of open-source data formats and tools, driven by upcoming observatories such as the Cherenkov Telescope Array (CTA). In this context, a community-driven, shared data format (the gamma-Astro-data-format, or GADF) and analysis tools such as Gammapy and ctools have been developed. So far, these …

Domain Wall Enabled Steep Slope Switching In Mos2 Transistors Towards Hysteresis-Free Operation, Jingfeng Song, Yubo Qi, Zhiyong Xiao, Kun Wang, Dawei Li, Seung-Hyun Kim, Angus I. Kingon, Andrew M. Rappe, Xia Hong

Department of Physics and Astronomy: Faculty Publications

The device concept of ferroelectric-based negative capacitance (NC) transistors offers a promising route for achieving energyefficient logic applications that can outperform the conventional semiconductor technology, while viable operation mechanisms remain a central topic of debate. In this work, we report steep slope switching in MoS₂ transistors back-gated by single-layer polycrystalline PbZr_0.35Ti_0.65O₃. The devices exhibit current switching ratios up to 8 × 10⁶ within an ultra-low gate voltage window of Vg = ±0:5 V and subthreshold swing (SS) as low as 9.7 mV decade⁻¹ at room temperature, transcending the 60 mV decade …

Orbit Propagation And Determination Algorithms For Satellite Ground Stations, Shamma Esmaeel Jamali

Theses

The satellite orbital parameters are essential for satellite operations. With these parameters, it is possible to estimate the satellite position in the recent past and near future, which is essential to effectively plan satellite operations and associate satellite telemetry with geographical locations.
However, for small or medium satellite operators who do not possess the infrastructure required to track their satellites, the problem of determining the satellite orbit is problematic. To access the orbit for their satellites, these organizations have to rely on third parties such as Celestrak. These entities provide the service free of charge but do not provide orbital …

Optimizing Switching Of Non-Linear Properties With Hyperbolic Metamaterials, James A. Ethridge, John G. Jones, Manuel R. Ferdinandus, Michael J. Havrilla, Michael A. Marciniak

Faculty Publications

Hyperbolic metamaterials have been demonstrated to have special potential in their linear response, but the extent of their non-linear response has not been extensively modeled or measured. In this work, novel non-linear behavior of an ITO/SiO₂ layered hyperbolic metamaterial is modeled and experimentally confirmed, specifically a change in the sign of the non-linear absorption with intensity. This behavior is tunable and can be achieved with a simple one-dimensional layered design. Fabrication was performed with physical vapor deposition, and measurements were conducted using the Z-scan technique. Potential applications include tunable optical switches, optical limiters, and tunable components of laser sources.

Interband Transitions And Critical Points Of Single-Crystal Thoria Compared With Urania, Christina L. Dugan, Lu Wang, Kai Zhang, James Matthew Mann, Martin M. Kimani, Wai-Ning Mei, Peter A. Dowben, James C. Petrosky

Faculty Publications

The interband transitions of UO₂ are validated independently through cathode luminescence. A picture emerges consistent with density functional theory. While theory is generally consistent with experiment, it is evident from the comparison of UO₂ and ThO₂ that the choice of functional can significantly alter the bandgap and some details of the band structure, in particular at the conduction band minimum. Strictly ab initio predictions of the optical properties of the actinide compounds, based on density functional theory alone, continue to be somewhat elusive.

Design And Modeling Of Superconducting Hardware For Implementing Quantum Stabilizers, Yebin Liu

Dissertations - ALL

Superconducting qubits are one of the leading systems for implementing quantum processors. Realizing fault-tolerant quantum computation requires some form of quantum error correction, which typically involves performing repeated stabilizer operations on groups of physical qubits in an array to form a logical qubit with enhanced protection against errors. Realizing a logical qubit that is suitable for running quantum algorithms requires an array with a significant number of physical qubits, which is extremely challenging. However, the physical qubit overhead can be reduced by lowering the error rate on the physical qubits. Current state-of-the-art superconducting qubit designs do not have robust protection …

Topological Phase Transitions And Berry-Phase Hysteresis In Exchange-Coupled Nanomagnets, Ahsan Ullah, Xin Li, Yunlong Jin, Rabindra Pahari, Lanping Yue, Xiaoshan S. Xu, Balamurugan Balasubramanian,, David J. Sellmyer, Ralph Skomski

Department of Physics and Astronomy: Faculty Publications

Topological phase in magnetic materials yields a quantized contribution to the Hall effect known as the topological Hall effect, which is often caused by skyrmions, with each skyrmion creating a magnetic flux quantum ±h/e. The control and understanding of topological properties in nanostructured materials is the subject of immense interest for both fundamental science and technological applications, especially in spintronics. In this work, the electron-transport properties and spin structure of exchange-coupled cobalt nanoparticles with an average particle size of 13.7 nm are studied experimentally and theoretically. Magnetic and Hall-effect measurements identify topological phase transitions in the exchange-coupled cobalt …

Electro-Optical Sensors For Atmospheric Turbulence Strength Characterization With Embedded Edge Ai Processing Of Scintillation Patterns, Ernst Polnau, Don L. N. Hettiarachchi, Mikhail A. Vorontsov

Electro-Optics and Photonics Faculty Publications

This study introduces electro-optical (EO) sensors (TurbNet sensors) that utilize a remote laser beacon (either coherent or incoherent) and an optical receiver with CCD camera and embedded edge AI computer (Jetson Xavier Nx) for in situ evaluation of the path-averaged atmospheric turbulence refractive index structure parameter C-n(2) at a high temporal rate. Evaluation of C-n(2) values was performed using deep neural network (DNN)-based real-time processing of short-exposure laser-beacon light intensity scintillation patterns (images) captured by a TurbNet sensor optical receiver. Several pre-trained DNN models were loaded onto the AI computer and used for TurbNet sensor performance evaluation in a set …

Spectroscopic Properties Of The Astrochemical Molecules [Al, O, Si]X (X = 0, +1), Jacqueline M. Friskey, Vincent J. Esposito, Tarek Trabelsi, Joseph S. Francisco

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Aluminum and silicon are present in large quantities in the interstellar medium, making the triatomic species consisting of both elements intriguing with regard to the foundations of astrochemistry. Spectroscopic parameters have been calculated via high-level ab initio methods to assist with laboratory and observational detection of [Al, O, Si]^x(x = 0,+1). All [Al, O, Si]M^x(x = 0,+1) isomers exist in the linear geometry, with linear AlOSi (X ²Π) and linear AlOSi⁺ (X¹Δ) being the most stable neutral and cationic species, respectively. Formation of the neutral species most likely occurs via reaction of …

Targeted Search For The Kinematic Dipole Of The Gravitational-Wave Background, Adrian Ka-Wai Chung, Alexander C. Jenkins, Joseph D. Romano, Mairi Sakellariadou

Physics & Astronomy Faculty Publications

There is growing interest in using current and future gravitational-wave interferometers to search for anisotropies in the gravitational-wave background. One guaranteed anisotropic signal is the kinematic dipole induced by our peculiar motion with respect to the cosmic rest frame, as measured in other full-sky observables such as the cosmic microwave background. Our prior knowledge of the amplitude and direction of this dipole is not explicitly accounted for in existing searches by LIGO/Virgo/KAGRA but could provide crucial information to help disentangle the sources which contribute to the gravitational-wave background. Here, we develop a targeted search pipeline which uses this prior knowledge …

Remote Surface Optical Phonon Scattering In Ferroelectric Ba0.6Sr0.4Tio3 Gated Graphene, Hanying Chen, Tianlin Li, Yifei Hao, Anil Rajapitamahuni, Zhiyong Xiao, Stefan Schoeche, Mathias Schubert, Xia Hong

Xia Hong Publications

We report the effect of remote surface optical (RSO) phonon scattering on carrier mobility in monolayer graphene gated by ferroelectric oxide. We fabricate monolayer graphene transistors back-gated by epitaxial (001) Ba0.6Sr0.4TiO3 films, with field effect mobility up to 23,000 cm² V⁻¹ s⁻¹ achieved. Switching ferroelectric polarization induces nonvolatile modulation of resistance and quantum Hall effect in graphene at low temperatures. Ellipsometry spectroscopy studies reveal four pairs of optical phonon modes in Ba_0.6Sr_0.4TiO₃, from which we extract RSO phonon frequencies. The temperature dependence of resistivity in graphene can be well accounted for …