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Full-Text Articles in Other Physics

Demonstrating Superresolution In Radar Range Estimation Using A Denoising Autoencoder, Robert Czupryniak, Abhishek Chakraborty, Andrew N. Jordan, John C. Howell Aug 2026

Demonstrating Superresolution In Radar Range Estimation Using A Denoising Autoencoder, Robert Czupryniak, Abhishek Chakraborty, Andrew N. Jordan, John C. Howell

Mathematics, Physics, and Computer Science Faculty Articles and Research

We apply machine learning methods to demonstrate radar range superresolution using a denoising autoencoder trained without supervision. Focusing on the estimation of a single physical parameter, the separation between two scatterers in the subwavelength regime, we constrain the network to a one-dimensional bottleneck layer with its size matched to the parameter dimensionality. We find that the bottleneck layer forms a reproducible, monotonic mapping with the true separation, showing that the network learns a low-dimensional representation directly aligned with the underlying physical parameter. We further show that this representation preserves the Fisher information of the signal, indicating that the network recovers …


The Trouble Of Energy: Theoretical Foundations Of Loop Quantum Gravity, Hallie Gift May 2026

The Trouble Of Energy: Theoretical Foundations Of Loop Quantum Gravity, Hallie Gift

Senior Honors Theses

While general relativity and quantum mechanics have proved to be successful theories with elegant explanations of special cases, an underlying theory is needed to harmonize their copious discrepancies. Popular theories to reconcile the two are broadly termed “quantum gravity,” which refers to theories that introduce a discretized component of gravity either by directly suggesting gravitational quanta or attempting to discretize spacetime geometry. Loop quantum gravity falls under the latter category; it respects the background independence intrinsic to general relativity while attempting to provide an explanation of underlying quantum behavior via Planck-scale-level geometrical discretization. This thesis aims to provide a primer …


Form And Fusion: The Art And Science Of Ceramics And Glass, Juniper J. Bauroth-Sherman, Kaleigh Evans Apr 2026

Form And Fusion: The Art And Science Of Ceramics And Glass, Juniper J. Bauroth-Sherman, Kaleigh Evans

Interdivisional Studies Presentations

The first Ceramics & Art class (IDS-110-F: ST: Ceramics) has completed an immersive, interdisciplinary exploration of stained glass and we’re excited to showcase it now. Through hands-on studio work, experiments, and design projects, we combined artistic expression with the science of glass—learning how physics and chemistry shape everything from color to strength and light interaction. The students have developed practical skills in cutting, grinding, foiling, soldering, and assembling stained-glass pieces, while also experimenting with thermal stress, light transmission, and color chemistry. Glass is now understood as not just as an art form, but as a dynamic material grounded in scientific …


On Links Between A Theorem Of Schoenberg, Rohlin Decompositions Of Measures, The Bochner-Minlos Theorem And The Fock Space, Daniel Alpay, Paula Cerejeiras, Palle Jorgensen, Uwe Kaehler Mar 2026

On Links Between A Theorem Of Schoenberg, Rohlin Decompositions Of Measures, The Bochner-Minlos Theorem And The Fock Space, Daniel Alpay, Paula Cerejeiras, Palle Jorgensen, Uwe Kaehler

Mathematics, Physics, and Computer Science Faculty Articles and Research

The main goal of this paper is to gain new results in stochastics by drawing on, and combining, different areas that are normally not considered to be related. Thus, in this paper we extend the previous class of Gaussian-like functions ML which will allow for future generalized stochastic processes in infinite dimensional analysis. We show that an approach similar to the one by the classical Bochner-Minlos theorem for the white-noise case can be achieved by using Gaussian-like functions belonging to a large family -the MLr classes (0 < r ≤∞). We show how Schoenberg’s theorem for positive definite functions on a Hilbert space allows to go beyond the classical setting of Bochner-Milnos theorem. Furthermore, we show that the application of the Rohlin’s disintegration theorem allows for a decomposition of the associated probability measures , see Theorems 3.2 and 4.3. We end this paper with several important examples of functions in these classes MLr and provide some interesting counterexamples, e.g. Theorem 7.4, to get a …


Physics Alumni Newsletter Spring 2026, Terry Goforth Jan 2026

Physics Alumni Newsletter Spring 2026, Terry Goforth

Physics Alumni Newsletter

Physics Alumni Newsletter

The Physics Alumni Newsletter is produced by the SWOSU Physics Department.

Our Engineering Physics students are recruited in fields such as electronics, aerospace, mechanical engineering, petroleum engineering and software engineering. Graduates also have careers in meteorology, architecture, education and more.


Guitar Amplifier Directivity, Rachel C. Edelman, Brian E. Anderson, Samuel D. Bellows, Timothy W. Leishman Jan 2026

Guitar Amplifier Directivity, Rachel C. Edelman, Brian E. Anderson, Samuel D. Bellows, Timothy W. Leishman

Directivity

No abstract provided.


Fish-Spec: Fast Identification System For Handheld Spectroscopy And Species Classification, Mitchell Sueker, Nicholas Mackinnon, Gregory Bearman, Amanda Tabb, Diane Kim, Rosalee S. Hellberg, Alireza Akhbardeh, Hamid Reza Marateb, Jianwei Qin, Moon Kim, Fartash Vasefi, Hossein Kashani Zadeh Nov 2025

Fish-Spec: Fast Identification System For Handheld Spectroscopy And Species Classification, Mitchell Sueker, Nicholas Mackinnon, Gregory Bearman, Amanda Tabb, Diane Kim, Rosalee S. Hellberg, Alireza Akhbardeh, Hamid Reza Marateb, Jianwei Qin, Moon Kim, Fartash Vasefi, Hossein Kashani Zadeh

Food Science Faculty Articles and Research

Accurate fish species identification is critical to prevent mislabeling and fraud in the seafood industry. We present a handheld multi-mode point spectroscopy system that combines fluorescence (365 and 395 nm excitation) and reflectance measurements in the visible to near-infrared (∼350–900 nm) and short-wave infrared (∼900–1700 nm) regions for rapid, non-destructive classification of fish fillets. Tissue spectra were acquired at 25 positions on 68 fillets from 11 species, in both frozen and thawed states. Feature-level fusion across all four modes enabled higher classification accuracy than any single mode alone. A global machine-learning model classified all species with 85 ± 2.8 %, …


Challenges In Developing Physical Intuition In College General Physics Courses, Vasiliy S. Znamenskiy, Rafael Niyazov Oct 2025

Challenges In Developing Physical Intuition In College General Physics Courses, Vasiliy S. Znamenskiy, Rafael Niyazov

Open Educational Resources

Many students can memorize formulas but struggle to feel what a newton, joule, or volt means; they treat formulas as plug-and-chug templates rather than descriptions of relationships among physical quantities. This presentation introduces three types of learning activities: (1) text-free (“no-text”) problems, in which carefully designed visuals replace prose to convey relationships and constraints; (2) anti-problems, which begin with a mathematical expression and ask students to imagine a physical situation it could describe; and (3) lab games that turn routine measurement into purposeful play, emphasizing estimation, scaling, and unit sense. We provide ready-made, Brightspace-compatible assessments alongside low-tech implementation options. The …


R12 Equivalent Resistance Reduction Steps, Vasiliy S. Znamenskiy, Rafael Niyazov Oct 2025

R12 Equivalent Resistance Reduction Steps, Vasiliy S. Znamenskiy, Rafael Niyazov

Open Educational Resources

We present a concise, step-by-step reduction of a symmetric resistor network to its equivalent resistance 𝑅12, emphasizing visual reasoning over algebraic brute force. By redrawing the circuit to expose symmetry, we identify equipotential node pairs joined by ideal conductors; the “bottom” bridging resistor is shown to carry zero current and is removed from consideration. The remaining topology reduces by two repeated series combinations, where each left/right pair of equal resistors collapses to 2R. The final network is a three-branch parallel combination (2𝑅∥𝑅∥2𝑅), yielding the closed-form result 𝑅12=𝑅/2. The procedure illustrates three transferable techniques for introductory circuit …


Citytech Algebra Based Physics Exam1 (Brightspace Quiz), Vasiliy S. Znamenskiy, Rafael Niyazov Oct 2025

Citytech Algebra Based Physics Exam1 (Brightspace Quiz), Vasiliy S. Znamenskiy, Rafael Niyazov

Open Educational Resources

This Brightspace-based Exam 1 assesses foundational concepts in algebra-based physics through short, auto-graded items designed to provide clear feedback. The exam targets core learning outcomes from the opening units of the course: measurement and unit analysis, significant figures, one-dimensional kinematics with constant acceleration (relationships among 𝑥, 𝑣, 𝑎, 𝑡), and basic problem-solving with proportional reasoning. Question formats include numerical entry multiple choice focused on common misconceptions, and brief conceptual prompts that test qualitative understanding before calculation. The item set emphasizes translating among verbal descriptions, diagrams, formulas, and graphs; checking the reasonableness of results; and communicating precision. Randomized parameters and pooled …


Examining The Accuracy Of The Omni Data In Representing Geomagnetic Storm Observations Near Earth And The Effect On Global Modeling, James T. Davis May 2025

Examining The Accuracy Of The Omni Data In Representing Geomagnetic Storm Observations Near Earth And The Effect On Global Modeling, James T. Davis

2025 Spring Honors Capstone Projects - Archive

The accuracy of OMNI dataset being propagated to bow shock nose and used to represent geomagnetic storms is a known issue. Inaccuracies of this data bring erroneous results in scientific endeavors therefore establishing the importance of accuracy and consistency. This case study examines the accuracy of the OMNI data and data near-Earth in representing geomagnetic storms with different drivers on global simulations. This research will include examples of global magnetosphere simulations, such as SWMF, driven with two storms driven by coronal mass ejections, and one driven by a high-speed stream using OMNI data and data near-Earth to illustrate potential variations …


The Mechanics Of Angular Momentum Generation In Discus Throwing, Andreas Maheras May 2025

The Mechanics Of Angular Momentum Generation In Discus Throwing, Andreas Maheras

Track and Field Faculty Publications

Angular momentum development in the back of the ring, during the first double and first single support, is of paramount importance in discus throwing because this is where almost all the angular momentum the thrower can generate will be generated. From a purely mechanical point of view, to achieve that, the thrower should keep her arms spread apart, and also actively throw both the right leg and the left arm and shoulders CCW. Those actions will collectively contribute in slowing down the lower body, as the thrower actively chooses to pass as much angular momentum to the upper body at …


Signal Modeling Of High Purity Germanium Detectors, Brooke Parker Thibodeau May 2025

Signal Modeling Of High Purity Germanium Detectors, Brooke Parker Thibodeau

Honors Scholar Theses

Pulse shape analysis can be used to analyze radiation incident on a semiconductor diode detector. Finite element analysis (FEA) can be used to simulate high purity germanium detectors with user-specified geometry, impurity concentration, and bias voltage. Subsequent streamline calculation can be used to conduct pulse shape analysis for single and multiple site gamma-ray interactions within the detector volume. Cross sections of the detector can be visualized by contour plots of the electric field, drift velocity magnitude, and collection time, as well as t30 and t90 rise-time values.


Charging And Discharging Capacitors: Brightspace Package Of An Arithmetic Quiz, Vasiliy Znamenskiy Apr 2025

Charging And Discharging Capacitors: Brightspace Package Of An Arithmetic Quiz, Vasiliy Znamenskiy

Open Educational Resources

Description:

This material is a quiz in the Brightspace Learning Management System (LMS). The quiz includes 10 physics problems on the topic of charging and discharging capacitors through a resistor.

The quiz assesses student understanding of key concepts, including voltage and charge of a capacitor, exponential functions, time constants, and dynamic changes in voltage and current.

Quiz problems are called in Brightspace LMS as arithmetic questions. The Problems give students random initial values to provide many quiz variants.

The quiz is appropriate for high school AP Physics or introductory college-level physics courses.

Key Features:

10-question quiz in Brightspace importable format …


Computational Modeling Of Astrophysical Systems, Leleya Iris Stallard Apr 2025

Computational Modeling Of Astrophysical Systems, Leleya Iris Stallard

Spring Showcase for Research and Creative Inquiry

This research project focuses on the computational modeling of astrophysical systems using Femap with NX Nastran. The goal was to simulate and analyze the vibrational behavior and structural deformation of celestial bodies under different material compositions and collision conditions. Materials such as iron, granite, titanium, and models for white dwarf stars were used to investigate how varying physical properties affect the systems' dynamic responses. Both isotropic and anisotropic models were created to represent realistic astrophysical materials. Through static and modal analyses, the study explored how internal structure and material stiffness influence the reaction of celestial objects to applied forces and …


Doping Hybrid Photopolymerisable Glass With Bodipy Photosensitiser: An Efficient Approach To Improve Uv-Resistance, Luca Sorridente, Tatsiana Mikulchyk, Metodej Dvoracek, Mikhail A. Filatov, Izabela Naydenova, Kevin P. Murphy Jan 2025

Doping Hybrid Photopolymerisable Glass With Bodipy Photosensitiser: An Efficient Approach To Improve Uv-Resistance, Luca Sorridente, Tatsiana Mikulchyk, Metodej Dvoracek, Mikhail A. Filatov, Izabela Naydenova, Kevin P. Murphy

Conference Papers

The development of photosensitive materials with improved performance and extended functionality is crucial for advancing holographic technologies. This study presents the modification and characterization of a recently reported photopolymerisable glass composition, focusing on achieving an optimal balance between maximizing photosensitivity of the material during recording and minimizing the impact of UV light on the performance of the recorded holographic structure. Building on these findings, the ultimate goal is to develop UV-resistant holographic optical elements for wavefront sensing in space applications. The research approach is based on introducing a photosensitiser with weaker UV absorption than the typically used in this material …


Scp 231 Dictionary + Example Problems [General Physics 1], Daniel Capic Jan 2025

Scp 231 Dictionary + Example Problems [General Physics 1], Daniel Capic

Open Educational Resources

Student-written definitions of key physics concepts that appear in SCP 231. There are also student-written word problems with links to instructor-created video solutions.


Atmospheric Chemistry Experiment (Ace) Winds, Matthew Wyatt, Peter F. Bernath, Chris Boone, Léo Lavy, Ryan Johnson Jan 2025

Atmospheric Chemistry Experiment (Ace) Winds, Matthew Wyatt, Peter F. Bernath, Chris Boone, Léo Lavy, Ryan Johnson

Chemistry & Biochemistry Faculty Publications

The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) uses limb geometry to measure transmittance spectra of Earth's atmosphere by solar occultation. Line-of-sight wind speeds can be derived via Doppler shifts of molecular lines in infrared spectra. The wind look direction angles relative to geodetic North are derived from geometry. We validate the new ACE version 5.3 (v.5.3) line-of-sight winds with MIGHTI and meteor radar vector wind observations and find a ±15 m/s sunrise/sunset shift above 80 km. We also compare line-of-sight winds from ACE-FTS v.5.2 and v.5.3 with vector winds from the MERRA-2, HWM14, and WACCM-X models. A ±15 m/s …


Exploring Physics Teacher Identity: Pathways Toward Equitable Instruction Among Teachers, Clausell Mathis, Jomo Mutegi, Turhan Carroll, Maya Patel, Andrea Wooley Jan 2025

Exploring Physics Teacher Identity: Pathways Toward Equitable Instruction Among Teachers, Clausell Mathis, Jomo Mutegi, Turhan Carroll, Maya Patel, Andrea Wooley

Teaching & Learning Faculty Publications

Physics teacher identity encompasses teachers' beliefs and views toward being a physics teacher. Physics teacher identity is influenced by teachers' perspectives on physics teaching and learning. Previous studies on teacher identity in general suggest that the construct is complex and malleable. Studies further suggest that it influences instructional methods, student engagement, and classroom environment. However, within physics education, there has yet to be an examination of how physics teacher identity influences "equitable" teaching approaches. This qualitative study sought to identify various dimensions of physics teacher identity and its implications for physics education research. We interviewed secondary and postsecondary physics teachers …


Physicists As Environmental Experts, Rachel Rothschild Jan 2025

Physicists As Environmental Experts, Rachel Rothschild

Articles

The question of which scientists are qualified to provide expert guidance in legal controversies is a perennial debate among scholars, judges, and lawyers. Scientists who participate in legal disputes can achieve enormous power and influence, not only over the case at hand but over long-term developments in legal doctrine. While these issues arise in many areas of the law, environmental litigation has been a particularly active site of contestations over epistemic authority. Courts have frequently relied on scientists to understand whether the government is justified in regulating pollution and who may be liable for environmental and public health harms.

This …


Moderate Physical Perspectivalism, Emily Adlam Dec 2024

Moderate Physical Perspectivalism, Emily Adlam

Philosophy Faculty Articles and Research

Recent developments in the foundations of physics have given rise to a class of views suggesting that physically meaningful descriptions must always be relativized to a physical perspective. In this article, I distinguish between strong physical perspectivalism, which maintains that all facts must be relativized to a perspective, and moderate physical perspectivalism, which maintains that all empirically meaningful descriptions must be relativized to a perspective. I argue that scientific evidence and philosophical considerations support moderate physical perspectivalism over strong physical perspectivalism. In particular, motivations connected to epistemic humility and the social nature of science are more compatible with the moderate …


Twist-Assisted All-Antiferromagnetic Tunnel Junction In The Atomic Limit, Yullang Chen, Kartik Samanta, Naafls A. Shahed, Haojle Zhang, Chi Fang, Arthur Ernst, Evgeny Y. Tsymbal, Stuart S.P. Parkin Jul 2024

Twist-Assisted All-Antiferromagnetic Tunnel Junction In The Atomic Limit, Yullang Chen, Kartik Samanta, Naafls A. Shahed, Haojle Zhang, Chi Fang, Arthur Ernst, Evgeny Y. Tsymbal, Stuart S.P. Parkin

Nebraska Center for Materials and Nanoscience: Faculty Publications

Antiferromagnetic spintronics1,2 shows great potential for high-density and ultrafast information devices. Magnetic tunnel junctions (MTJs), a key spintronic memory component that are typically formed from ferromagnetic materials, have seen rapid developments very recently using antiferromagnetic materials3,4. Here we demonstrate a twisting strategy for constructing all-antiferromagnetic tunnel junctions down to the atomic limit. By twisting two bilayers of CrSBr, a 2D antiferromagnet (AFM), a more than 700% nonvolatile tunnelling magnetoresistance (TMR) ratio is shown at zero field (ZF) with the entire twisted stack acting as the tunnel barrier. This is determined by twisting two CrSBr monolayers for which the TMR …


Improving 2–5 Qubit Quantum Phase Estimation Circuits Using Machine Learning, Charles Woodrum, Torrey J. Wagner, David E. Weeks May 2024

Improving 2–5 Qubit Quantum Phase Estimation Circuits Using Machine Learning, Charles Woodrum, Torrey J. Wagner, David E. Weeks

Faculty Publications

Quantum computing has the potential to solve problems that are currently intractable to classical computers with algorithms like Quantum Phase Estimation (QPE); however, noise significantly hinders the performance of today’s quantum computers. Machine learning has the potential to improve the performance of QPE algorithms, especially in the presence of noise. In this work, QPE circuits were simulated with varying levels of depolarizing noise to generate datasets of QPE output. In each case, the phase being estimated was generated with a phase gate, and each circuit modeled was defined by a randomly selected phase. The model accuracy, prediction speed, overfitting level …


Gate-Controlled Supercurrent Effect In Dry-Etched Dayem Bridges Of Non-Centrosymmetric Niobium Rhenium, Jennifer Koch, Carla Cirillo, Sebastiano Battisti, Leon Ruf, Zahra Makhdoumi Kakhaki, Alessandro Paghi, Armen Gulian, Serafim Teknowijoyo, Giorgio De Simoni, Francesco Giazotto, Carmine Attanasio, Elke Scheer, Angelo Di Bernardo Apr 2024

Gate-Controlled Supercurrent Effect In Dry-Etched Dayem Bridges Of Non-Centrosymmetric Niobium Rhenium, Jennifer Koch, Carla Cirillo, Sebastiano Battisti, Leon Ruf, Zahra Makhdoumi Kakhaki, Alessandro Paghi, Armen Gulian, Serafim Teknowijoyo, Giorgio De Simoni, Francesco Giazotto, Carmine Attanasio, Elke Scheer, Angelo Di Bernardo

Mathematics, Physics, and Computer Science Faculty Articles and Research

The application of a gate voltage to control the superconducting current flowing through a nanoscale superconducting constriction, named as gate-controlled supercurrent (GCS), has raised great interest for fundamental and technological reasons. To gain a deeper understanding of this effect and develop superconducting technologies based on it, the material and physical parameters crucial for the GCS effect must be identified. Top-down fabrication protocols should also be optimized to increase device scalability, although studies suggest that top-down fabricated devices are more resilient to show a GCS. Here, we investigate gated superconducting nanobridges made with a top-down fabrication process from thin films of …


Myeloid-Derived Suppressor Cell Mitochondrial Fitness Governs Chemotherapeutic Efficacy In Hematologic Malignancies, Saeed Daneshmandi, Jee Eun Choi, Qi Yan, Cameron R. Macdonald, Manu Pandey, Mounika Goruganthu, Nathan Roberts, Prashant K. Singh, Richard M. Higashi, Andrew N. Lane, Teresa W-M Fan, Jianmin Wang, Philip L. Mccarthy, Elizabeth A. Repasky, Hemn Mohammadpour Mar 2024

Myeloid-Derived Suppressor Cell Mitochondrial Fitness Governs Chemotherapeutic Efficacy In Hematologic Malignancies, Saeed Daneshmandi, Jee Eun Choi, Qi Yan, Cameron R. Macdonald, Manu Pandey, Mounika Goruganthu, Nathan Roberts, Prashant K. Singh, Richard M. Higashi, Andrew N. Lane, Teresa W-M Fan, Jianmin Wang, Philip L. Mccarthy, Elizabeth A. Repasky, Hemn Mohammadpour

Markey Cancer Center Faculty Publications

Myeloid derived suppressor cells (MDSCs) are key regulators of immune responses and correlate with poor outcomes in hematologic malignancies. Here, we identify that MDSC mitochondrial fitness controls the efficacy of doxorubicin chemotherapy in a preclinical lymphoma model. Mechanistically, we show that triggering STAT3 signaling via β2-adrenergic receptor (β2-AR) activation leads to improved MDSC function through metabolic reprogram- ing, marked by sustained mitochondrial respiration and higher ATP generation which reduces AMPK signaling, altering energy metabolism. Furthermore, induced STAT3 signaling in MDSCs enhances glutamine consumption via the TCA cycle. Metabolized glutamine generates itaconate which downregulates mitochondrial reactive oxygen species via regulation of …


Spacetime Geometry Of Acoustics And Electromagnetism, Lucas Burns, Tatsuya Daniel, Stephon Alexander, Justin Dressel Feb 2024

Spacetime Geometry Of Acoustics And Electromagnetism, Lucas Burns, Tatsuya Daniel, Stephon Alexander, Justin Dressel

Mathematics, Physics, and Computer Science Faculty Articles and Research

Both acoustics and electromagnetism represent measurable fields in terms of dynamical potential fields. Electromagnetic force-fields form a spacetime bivector that is represented by a dynamical energy–momentum 4-vector potential field. Acoustic pressure and velocity fields form an energy–momentum density 4-vector field that is represented by a dynamical action scalar potential field. Surprisingly, standard field theory analyses of spin angular momentum based on these traditional potential representations contradict recent experiments, which motivates a careful reassessment of both theories. We analyze extensions of both theories that use the full geometric structure of spacetime to respect essential symmetries enforced by vacuum wave propagation. The …


Superconducting Polycrystalline Rhenium Films Deposited At Room Temperature, Serafim Teknowijoyo, Armen Gulian Jan 2024

Superconducting Polycrystalline Rhenium Films Deposited At Room Temperature, Serafim Teknowijoyo, Armen Gulian

Mathematics, Physics, and Computer Science Faculty Articles and Research

We report on magnetron deposition of thin superconducting rhenium films on sapphire substrates. During the deposition, substrates were held at ambient temperature. Critical temperature of the films is Tc ~ 3.6 K. Films have polycrystalline structure, and grazing incidence X-ray diffractometry indicates that crystalline lattice parameters are somewhat larger compared to the bulk ones. Magnetoresistive and AC/DC susceptibilities allowed us to determine Hc1 and Hc2 of these films, as well as estimate coherence length ξ(0) and magnetic penetration depth λL(0). We also provide information on surface morphology of these films.


Phase-Slip Centers As Cooling Engines, Iris Mowgood, Serafim Teknowijoyo, Sara Chahid, Armen Gulian Jan 2024

Phase-Slip Centers As Cooling Engines, Iris Mowgood, Serafim Teknowijoyo, Sara Chahid, Armen Gulian

Mathematics, Physics, and Computer Science Faculty Articles and Research

Based on time-dependent Ginzburg-Landau system of equations, Éliashberg’s kinetic equations and finite element modeling, we analyze phonon emission by the phase-slip centers in superconducting filaments. Our results show that in the dissipative regime with these centers, thin superconducting filaments can be effective in originating not only positive but also negative thermal fluxes, i.e., they both generate and absorb phonons. In a stationary oscillatory regime, at a given moment of time, this generation and absorption of phonons reveals itself as positive and negative spectrum of phonons at different spectral ranges. Moreover, at a given spectral range, the emission reverses its sign …


Superconductivity Of Amorphous And Crystalline Re–Lu Films, Serafim Teknowijoyo, Armen Gulian Jan 2024

Superconductivity Of Amorphous And Crystalline Re–Lu Films, Serafim Teknowijoyo, Armen Gulian

Mathematics, Physics, and Computer Science Faculty Articles and Research

We report on superconducting properties of a novel material: rhenium-lutetium films. Different compositions of RexLu binary are explored from x ≈ 3.8 to close to pure Re stoichiometry. The highest critical temperature, up to 7 K, is obtained for x ≈ 10.5 in accordance with electron dispersive spectroscopy results. Depending on the deposition conditions, polycrystalline or amorphous films are obtainable, both of which are interesting for practical use. Crystalline structure of polycrystalline phase is identified as a non-centrosymmetric superconductor using grazing incidence x-ray diffractometry. Superconducting properties were characterized both resistively and magnetically. Magnetoresistivity and AC/DC susceptibility measurements allowed …


Some Remarks On Possible Superconductivity Of Composition Pb9Cup6O25, Pablo Abramian-Barco, A. Kuzanyan, Vahan Nikoghosyan, Serafim Teknowijoyo, Armen Gulian Jan 2024

Some Remarks On Possible Superconductivity Of Composition Pb9Cup6O25, Pablo Abramian-Barco, A. Kuzanyan, Vahan Nikoghosyan, Serafim Teknowijoyo, Armen Gulian

Mathematics, Physics, and Computer Science Faculty Articles and Research

A material called LK-99, a modified-lead apatite crystal structure with the composition Pb10 – xCux(PO4)6O (0.9 < x < 1.1) has been reported to be an above-room-temperature superconductor at ambient pressure. It is hard to expect that it will be straightforward for other groups to reproduce the original results. We provide here some remarks which may be helpful for a success.