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Polaron Problems In Ultracold Atoms: Role Of A Fermi Sea Across Different Spatial Dimensions And Quantum Fluctuations Of A Bose Medium, Hiroyuki Tajima, Junichi Takahashi, Simeon I. Mistakidis, Eiji Nakano, Kei Iida Mar 2021

Polaron Problems In Ultracold Atoms: Role Of A Fermi Sea Across Different Spatial Dimensions And Quantum Fluctuations Of A Bose Medium, Hiroyuki Tajima, Junichi Takahashi, Simeon I. Mistakidis, Eiji Nakano, Kei Iida

Physics Faculty Research & Creative Works

The Notion Of A Polaron, Originally Introduced In The Context Of Electrons In Ionic Lattices, Helps Us To Understand How A Quantum Impurity Behaves When Being Immersed In And Interacting With A Many-Body Background. We Discuss The Impact Of The Impurities On The Medium Particles By Considering Feedback Effects From Polarons That Can Be Realized In Ultracold Quantum Gas Experiments. In Particular, We Exemplify The Modifications Of The Medium In The Presence Of Either Fermi Or Bose Polarons. Regarding Fermi Polarons We Present A Corresponding Many-Body Diagrammatic Approach Operating At Finite Temperatures And Discuss How Mediated Two-And Three-Body Interactions Are …


Extracting The Number Of Short Range Correlated Nucleon Pairs From Inclusive Electron Scattering Data, R. Weiss, A. W. Denniston, J. R. Pybus, O. Hen, E. Piasetzky, A. Schmidt, L. B. Weinstein, N. Barnea Mar 2021

Extracting The Number Of Short Range Correlated Nucleon Pairs From Inclusive Electron Scattering Data, R. Weiss, A. W. Denniston, J. R. Pybus, O. Hen, E. Piasetzky, A. Schmidt, L. B. Weinstein, N. Barnea

Physics Faculty Publications

The extraction of the relative abundances of short-range correlated (SRC) nucleon pairs from inclusive electron scattering is studied using the generalized contact formalism (GCF) with several nuclear interaction models. GCF calculations can reproduce the observed scaling of the cross-section ratios for nuclei relative to deuterium at high xB and large Q2, a2 = (σA/A)/(σd/2). In the nonrelativistic instant-form formulation, the calculation is very sensitive to the model parameters and only reproduces the data using parameters that are inconsistent with ab initio many-body calculations. Using a light-cone GCF formulation significantly decreases this sensitivity …


Entangling Lattice-Trapped Bosons With A Free Impurity: Impact On Stationary And Dynamical Properties, Maxim Pyzh, Kevin Keiler, Simeon I. Mistakidis, Peter Schmelcher Mar 2021

Entangling Lattice-Trapped Bosons With A Free Impurity: Impact On Stationary And Dynamical Properties, Maxim Pyzh, Kevin Keiler, Simeon I. Mistakidis, Peter Schmelcher

Physics Faculty Research & Creative Works

We Address The Interplay Of Few Lattice Trapped Bosons Interacting With An Impurity Atom In A Box Potential. For The Ground State, A Classification Is Performed Based On The Fidelity Allowing To Quantify The Susceptibility Of The Composite System To Structural Changes Due To The Intercomponent Coupling. We Analyze The Overall Response At The Many-Body Level And Contrast It To The Single-Particle Level. By Inspecting Different Entropy Measures We Capture The Degree Of Entanglement And Intraspecies Correlations For A Wide Range Of Intra- And Intercomponent Interactions And Lattice Depths. We Also Spatially Resolve The Imprint Of The Entanglement On The …


Optical Study Of 2-D Detonation Wave Stability, Eulaine T. Grodner Mar 2021

Optical Study Of 2-D Detonation Wave Stability, Eulaine T. Grodner

Theses and Dissertations

Fundamental optical detonation study of detonations constricted to a 2-d plane propagation, and detonations propagating around a curve. All images were processed using modern image processing techniques. The optical techniques used were shadowgraph, Schlieren, and chemiluminescence. In the 2-Dstraight channels, it was determined wave stability was a factor of cell size. It was also determined the detonation wave thickness (area between the combustion and shockwave) was a factor of how much heat available for the detonation. For the detonations propagating around a curve, it was determined the three main classifications of wave stability were stable, unstable, and detonation wave restart. …


Impendance Probe Payload Development For Space-Based Joint Service Collaboration, Brian T. Kay Mar 2021

Impendance Probe Payload Development For Space-Based Joint Service Collaboration, Brian T. Kay

Theses and Dissertations

Collaborations utilizing small spacecraft in near earth orbit between the U. S. Coast Guard Academy (CGA), Naval Research Lab (NRL), the U. S. Naval Academy (USNA), and the Air Force Institute of Technology (AFIT) have initiated scientific and engineering space-based experiments. Sourced opportunities like the VaSpace ThinSat missions have provided a platform for payload, sensor, and experiment development that would have otherwise been resource prohibitive. We have constructed an impedance probe payload derived from the existing ‘Space PlasmA Diagnostic suitE’ (SPADE) mission operating from NASA’s International Space Station. Currently both space and laboratory plasmas are investigated with AC impedance measurements …


Error Detection In Quantum Algorithms, Simeon R. Hanks Mar 2021

Error Detection In Quantum Algorithms, Simeon R. Hanks

Theses and Dissertations

Quantum computers need to be able to control highly entangled quantum states in the presence of environmental perturbations that lead to errors in calculations. Progress in superconducting qubits has enabled the development of computers capable of running small quantum circuits. The current era of Noise Intermediate Scale Quantum computing has a high error rate. To alleviate this error rate we apply an encoding scheme that allows us to remove results with known errors improving the quality of our results. The encoding uses multiple qubits as a single logical qubit and balances the natural tendency of state-of-the-art quantum computers to decohere …


Ab Initio Spectroscopy Of Natural And Artificial Fire Contaminants For V/W Band Frequency Signal Absorbance, Matthew B. Husk Mar 2021

Ab Initio Spectroscopy Of Natural And Artificial Fire Contaminants For V/W Band Frequency Signal Absorbance, Matthew B. Husk

Theses and Dissertations

The rotation and vibration spectral properties including frequencies and intensities for highly concentrated molecules present in wildland and artificial fires have been studied. These properties were used to determine absorption and its effect in a link budget analysis. Absorption in link budget analyses is commonly accounted for via line-by-line methodology aided by HITRAN documented intensities. Limited, if any, customization of spectral properties is available with HITRAN and other spectral databases. Ab initio calculations with different atomic basis sets were employed to obtain structures, dipole moments, rotational-vibrational frequencies and intensities, as well as various coupling parameters. Anharmonic corrections to the vibrational …


Dynamic Holography In Resonant Nonlinear Media: Theory And Application, Jonathan E. Slagle Mar 2021

Dynamic Holography In Resonant Nonlinear Media: Theory And Application, Jonathan E. Slagle

Theses and Dissertations

Two beam coupling (TBC) is a coherent interaction in which energy is transferred from one laser beam to another and has promising applications in real-time holography and coherent beam combing. We have recently shown efficient degenerate frequency TBC for counter-propagation geometries in isotropic two-photon absorbing media pumped with a nanosecond pulsed laser. When an interference pattern is generated in this media, single and two photon absorption initiates a population redistribution resulting in a holographic grating with the same modulation period and phase initially. However, due to temporal convolution of self- and cross-phase modulation, the grating will begin to shift in …


Topological Realizations Of Entangling Quantum Gates, Adrian D. Scheppe Mar 2021

Topological Realizations Of Entangling Quantum Gates, Adrian D. Scheppe

Theses and Dissertations

Topological systems are immune to decoherence and provide a hunting ground for qubits that are fault tolerant. The process of calculating linear operator representations of Majorana fermion exchanges or braids is well known and well documented; however, there is no documented intuition or algorithm which provides the opposite; braids from quantum gates. In this document, all possible linear representations of single, double, triple, and quadruple qubit gates are calculated to find several key patterns which provide crucial insight into the manifestation of qubit gates. A n x n gate will require n + 2 Majoranas with ½n + 1 trivial …


Error Reduction For The Determination Of Transverse Moduli Of Single-Strand Carbon Fibers Via Atomic Force Microscopy, Joshua D. Frey Mar 2021

Error Reduction For The Determination Of Transverse Moduli Of Single-Strand Carbon Fibers Via Atomic Force Microscopy, Joshua D. Frey

Theses and Dissertations

The transverse modulus of single strand carbon fibers is measured using PeakForce Atomic Force Microscopy - Quantitative Nanomechanical Measurement to less than 5 percent error for 11 types of carbon fiber with longitudinal moduli between 924-231 GPA, including export-controlled fibers. Statistical methods are employed to improve the quality of data to exclude outliers within an measurement and within the sample set. A positive linear correlation between the longitudinal and transverse modulus with an R2=0.76 is found. Pitch-based fibers exhibit lower measurement error than PAN-based fibers, while PAN fibers exhibited no apparent modulus correlation when the Pitch fibers are …


Development Of 3d In Vitro Tissue Models For The Analysis Of Solar Radiation Damage Of Skin, Ulises Lopez Gonzalez Mar 2021

Development Of 3d In Vitro Tissue Models For The Analysis Of Solar Radiation Damage Of Skin, Ulises Lopez Gonzalez

Doctoral

The aim of this work was to investigate changes to the molecular composition and conformation of HaCaT cells as a result of simulated solar radiation in a 3D in vitro skin model by Raman spectroscopy. The process to achieve this goal was performed in three main stages: (1) optimisation of the working concentration and volume of two 3D membranes, used as a structural support in the skin model; (2) the construction of the 3D in vitro skin model and; (3) the investigation of the dose-dependent effects of solar radiation on HaCaT cells in the skin model in comparison with the …


Remote Mesoscopic Signatures Of Induced Magnetic Texture In Graphene, N. Arabchigavkani, R. Somphonsane, H. Ramamoorthy, G. He, J. Nathawat, S. Yin, B. Barut, K. He, M. D. Randle, R. Dixit, K. Sakanashi, N. Aoki, K. Zhang, L. Wang, W. N. Mei, Peter Dowben, J. Fransson, J. P. Bird Feb 2021

Remote Mesoscopic Signatures Of Induced Magnetic Texture In Graphene, N. Arabchigavkani, R. Somphonsane, H. Ramamoorthy, G. He, J. Nathawat, S. Yin, B. Barut, K. He, M. D. Randle, R. Dixit, K. Sakanashi, N. Aoki, K. Zhang, L. Wang, W. N. Mei, Peter Dowben, J. Fransson, J. P. Bird

Peter Dowben Publications

Mesoscopic conductance fluctuations are a ubiquitous signature of phase-coherent transport in small conductors, exhibiting universal character independent of system details. In this Letter, however, we demonstrate a pronounced breakdown of this universality, due to the interplay of local and remote phenomena in transport. Our experiments are performed in a graphene-based interaction-detection geometry, in which an artificial magnetic texture is induced in the graphene layer by covering a portion of it with a micromagnet. When probing conduction at some distance from this region, the strong influence of remote factors is manifested through the appearance of giant conductance fluctuations, with amplitude much …


A Jones Calculus Approach To High-Order Harmonic Generation In Solids, Erin Crites, Shima Gholam-Mirzaei, Zain Khan, Mamta Singh, John E. Beetar Feb 2021

A Jones Calculus Approach To High-Order Harmonic Generation In Solids, Erin Crites, Shima Gholam-Mirzaei, Zain Khan, Mamta Singh, John E. Beetar

The Pegasus Review: UCF Undergraduate Research Journal

High-order harmonics from bulk solids were first observed in 2011 by focusing an intense mid-infrared laser through a bulk crystal and detecting the harmonics in a transmission geometry. Due to birefringence and possible nonlinear effects in bulk crystal, the polarization state of the laser can change as it propagates through the crystal in this transmission geometry. This can result in harmonic signal generated with an unknown polarization of light, disrupting the signal. Alternatives to bulk crystal, such as a reflection geometry or thin films, are not always ideal – reflection geometry can introduce nonlinear reflection coefficients, while crystalline thin films …


Independently Controlling Stochastic Field Realization Magnitude And Phase Statistics For The Construction Of Novel Partially Coherent Sources, Milo W. Hyde Iv Feb 2021

Independently Controlling Stochastic Field Realization Magnitude And Phase Statistics For The Construction Of Novel Partially Coherent Sources, Milo W. Hyde Iv

Faculty Publications

In this paper, we present a method to independently control the field and irradiance statistics of a partially coherent beam. Prior techniques focus on generating optical field realizations whose ensemble-averaged autocorrelation matches a specified second-order field moment known as the cross-spectral density (CSD) function. Since optical field realizations are assumed to obey Gaussian statistics, these methods do not consider the irradiance moments, as they, by the Gaussian moment theorem, are completely determined by the field’s first and second moments. Our work, by including control over the irradiance statistics (in addition to the CSD function), expands existing synthesis approaches and allows …


Impact Of Dynamic Sub-Populations Within Grafted Chains On The Protein Binding And Colloidal Stability Of Pegylated Nanoparticles, Delyan Hristov, Hender Lopez, Yannick Ortin, Kate O'Sullivan, Kenneth A. Dawson, Dermot F. Brougham Feb 2021

Impact Of Dynamic Sub-Populations Within Grafted Chains On The Protein Binding And Colloidal Stability Of Pegylated Nanoparticles, Delyan Hristov, Hender Lopez, Yannick Ortin, Kate O'Sullivan, Kenneth A. Dawson, Dermot F. Brougham

Articles

Polyethylene glycol grafting has played a central role in preparing the surfaces of nano-probes for biological interaction, to extend blood circulation times and to modulate protein recognition and cellular uptake. However, the role of PEG graft dynamics and conformation in determining surface recognition processes is poorly understood primarily due to the absence of a microscopic picture of the surface presentation of the polymer. Here a detailed NMR analysis reveals three types of dynamic ethylene glycol units on PEG-grafted SiO2 nanoparticles (NPs) of the type commonly evaluated as long-circulating theranostic nano-probes; a narrow fraction with fast dynamics associated with the chain …


Spin Superfluidity In Noncollinear Antiferromagnets, Bo Li, Alexey Kovalev Feb 2021

Spin Superfluidity In Noncollinear Antiferromagnets, Bo Li, Alexey Kovalev

Department of Physics and Astronomy: Faculty Publications

We explore the spin superfluid transport in exchange interaction dominated three-sublattice antiferromagnets. The system in the long-wavelength regime is described by an $SO(3)$ invariant field theory. Additional corrections from Dzyaloshinskii-Moriya interactions or anisotropies can break the symmetry; however, the system still approximately holds a $U(1)$-rotation symmetry. Thus, the power-law spatial decay signature of spin superfluidity is identified in a nonlocal-measurement setup where the spin injection is described by the generalized spin-mixing conductance. We suggest iron jarosites as promising material candidates for realizing our proposal.


Coarse-Grained Simulation Of Pegylated And Tethered Protein Devices At All Experimentally Accessible Surface Residues On Β-Lactamase For Stability Analysis And Comparison, Addison K. Smith, Mehran Sultani, Joshua Wilkerson, Brandon Timmerman, Emily Long Zhao, Bradley C. Bundy, Thomas A. Knotts Feb 2021

Coarse-Grained Simulation Of Pegylated And Tethered Protein Devices At All Experimentally Accessible Surface Residues On Β-Lactamase For Stability Analysis And Comparison, Addison K. Smith, Mehran Sultani, Joshua Wilkerson, Brandon Timmerman, Emily Long Zhao, Bradley C. Bundy, Thomas A. Knotts

Faculty Publications

PEGylated and surface-tethered proteins are used in a variety of biotechnological applications, but traditional methods offer little control over the placement of the functionalization sites on the protein. Fortunately, recent experimental methods functionalize the protein at any location on the amino acid sequence, so the question becomes one of selecting the site that will result in the best protein function. This work shows how molecular simulation can be used to screen potential attachment sites for surface tethering or PEGylation. Previous simulation work has shown promise in this regard for a model protein, but these studies are limited to screening only …


Insights Into Searches For Anisotropies In The Nanohertz Gravitational-Wave Background, Y. Ali-Haïmoud, Tristan L. Smith, C. M. F. Mingarelli Feb 2021

Insights Into Searches For Anisotropies In The Nanohertz Gravitational-Wave Background, Y. Ali-Haïmoud, Tristan L. Smith, C. M. F. Mingarelli

Physics & Astronomy Faculty Works

Within the next several years pulsar timing arrays (PTAs) are positioned to detect the stochastic gravitational-wave background (GWB) likely produced by the collection of inspiralling supermassive black holes binaries, and potentially constrain some exotic physics. So far most of the pulsar timing data analysis has focused on the monopole of the GWB, assuming it is perfectly isotropic. The natural next step is to search for anisotropies in the GWB. In this paper, we use the recently developed PTA Fisher matrix to gain insights into optimal search strategies for GWB anisotropies. For concreteness, we apply our results to the European Pulsar …


Determination Of The Rydberg Constant From The Emission Spectra Of H And He+, Kyle D. Shaffer Feb 2021

Determination Of The Rydberg Constant From The Emission Spectra Of H And He+, Kyle D. Shaffer

Ramifications

Abstract

In this experiment, the Rydberg constants for the hydrogen atom and He+ were determined by analysis of the emission spectra of Hand He, respectively, in comparison to the principal quantum numbers of each transition. Using both a hydrogen and then a helium atomic lamp attached to a 0.5 m grating spectrometer and a photomultiplier detector (PMT), a change in voltage detected by the PMT can be paired with a corresponding wavelength passing through the spectrometer from each emission peak in the visible to ultraviolet range. The peaks acquired from this change in voltage were analyzed to find their …


Arctic Observations And Numerical Simulations Of Surface Wind Effects On Multi-Angle Snowflake Camera Measurements, Kyle E. Fitch, Chaoxun Hang, Ahmad Talaei, Timothy J. Garrett Feb 2021

Arctic Observations And Numerical Simulations Of Surface Wind Effects On Multi-Angle Snowflake Camera Measurements, Kyle E. Fitch, Chaoxun Hang, Ahmad Talaei, Timothy J. Garrett

Physics Student Research

Ground-based measurements of frozen precipitation are heavily influenced by interactions of surface winds with gauge-shield geometry. The Multi-Angle Snowflake Camera (MASC), which photographs hydrometeors in free-fall from three different angles while simultaneously measuring their fall speed, has been used in the field at multiple midlatitude and polar locations both with and without wind shielding. Here, we present an analysis of Arctic field observations – with and without a Belfort double Alter shield – and compare the results to computational fluid dynamics (CFD) simulations of the airflow and corresponding particle trajectories around the unshielded MASC. MASC-measured fall speeds compare well with …


Flavor-Dependent Radiative Corrections In Coherent Elastic Neutrino-Nucleus Scattering, Oleksandr Tomalak, Pedro Machado, Vishvas Pandey, Ryan Plestid Feb 2021

Flavor-Dependent Radiative Corrections In Coherent Elastic Neutrino-Nucleus Scattering, Oleksandr Tomalak, Pedro Machado, Vishvas Pandey, Ryan Plestid

Physics and Astronomy Faculty Publications

We calculate coherent elastic neutrino-nucleus scattering cross sections on spin-0 nuclei (e.g. 40Ar and 28Si) at energies below 100 MeV within the Standard Model and account for all effects of permille size. We provide a complete error budget including uncertainties at nuclear, nucleon, hadronic, and quark levels separately as well as perturbative error. Our calculation starts from the four-fermion effective field theory to explicitly separate heavy-particle mediated corrections (which are absorbed by Wilson coefficients) from light-particle contributions. Electrons and muons running in loops introduce a non- trivial dependence on the momentum transfer due to their relatively light masses. …


The Potential Of Raman Spectroscopy In The Diagnosis Of Dysplastic And Malignant Oral Lesions, Ola Ibrahim, M. Toner, Steven Flint, Hugh Byrne, Fiona Lyng Feb 2021

The Potential Of Raman Spectroscopy In The Diagnosis Of Dysplastic And Malignant Oral Lesions, Ola Ibrahim, M. Toner, Steven Flint, Hugh Byrne, Fiona Lyng

Articles

Early diagnosis, treatment and/or surveillance of oral premalignant lesions are important in preventing progression to oral squamous cell carcinoma (OSCC). The current gold standard is through histopathological diagnosis, which is limited by inter and intra observer and sampling errors. The objective of this work was to use Raman spectroscopy to discriminate between benign, mild, moderate and severe dysplasia and OSCC in formalin fixed paraffin preserved (FFPP) tissues. The study included 72 different pathologies from which 17 were benign lesions, 20 mildly dysplastic, 20 moderately dysplastic, 10 severely dysplastic and 5 invasive OSCC. The glass substrate and paraffin wax background were …


Globular Clusters As Tracers Of The Dark Matter Content Of Dwarfs In Galaxy Clusters, Jessica E. Doppel, Laura V. Sales, Julio F. Navarro, Mario G. Abadi, Eric W. Peng, Elisa Toloba, Felipe Ramos-Almendares Feb 2021

Globular Clusters As Tracers Of The Dark Matter Content Of Dwarfs In Galaxy Clusters, Jessica E. Doppel, Laura V. Sales, Julio F. Navarro, Mario G. Abadi, Eric W. Peng, Elisa Toloba, Felipe Ramos-Almendares

Pacific Faculty Work

Globular clusters (GCs) are often used to estimate the dark matter content of galaxies, especially dwarf galaxies, where other kinematic tracers are lacking. These estimates typically assume spherical symmetry and dynamical equilibrium, assumptions that may not hold for the sparse GC population of dwarfs in galaxy clusters. We use a catalogue of GCs tagged on to the Illustris simulation to study the accuracy of GC-based mass estimates. We focus on galaxies in the stellar mass range 108-1011.8 M⊙ identified in nine simulated Virgo-like clusters. Our results indicate that mass estimates are, on average, accurate in systems with GC numbers NGC …


Measurement Of Time-Dependent Cp Violation Parameters In B0 → K0 S K0 S K0 S Decays At Belle, K. H. Kang, H. Park, T. Higuchi, K. Miyabayashi, K. Miyabayashi, K. Sumisawa, I. Adachi, J. K. Ahn, H. Aihara, S. Al Said, D. M. Asner, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, A. M. Bakich, P. Behera, Milind Purohit, Et. Al. Feb 2021

Measurement Of Time-Dependent Cp Violation Parameters In B0 → K0 S K0 S K0 S Decays At Belle, K. H. Kang, H. Park, T. Higuchi, K. Miyabayashi, K. Miyabayashi, K. Sumisawa, I. Adachi, J. K. Ahn, H. Aihara, S. Al Said, D. M. Asner, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, A. M. Bakich, P. Behera, Milind Purohit, Et. Al.

Faculty Publications

We measure the time-dependent CPviolation parameters in B0 → K0 S K0 S K0 S decays using 772 × 106 BB̅ pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The obtained mixing-induced and direct CP asymmetries are −0.71 ± 0.23 (stat) ± 0.05 (syst) and 0.12 ± 0.16 (stat) ± 0.05 (syst), respectively. These values are consistent with the Standard Model predictions. The significance of CP violation differs from zero by 2.5 standard deviations.


Measurement Of Time-Dependent Cp Violation Parameters In B0 → K0 S K0 S K0 S Decays At Belle, K. H. Kang, H. Park, T. Higuchi, K. Miyabayashi, K. Sumisawa, I. Adachi, J. K. Ahn, H. Aihara, S. Al Said, D. M. Asner, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, A. M. Bakich, P. Behera, C. Beleño, J. Bennett, Milind Purohit, Et. Al. Feb 2021

Measurement Of Time-Dependent Cp Violation Parameters In B0 → K0 S K0 S K0 S Decays At Belle, K. H. Kang, H. Park, T. Higuchi, K. Miyabayashi, K. Sumisawa, I. Adachi, J. K. Ahn, H. Aihara, S. Al Said, D. M. Asner, V. Aulchenko, T. Aushev, R. Ayad, V. Babu, S. Bahinipati, A. M. Bakich, P. Behera, C. Beleño, J. Bennett, Milind Purohit, Et. Al.

Faculty Publications

We measure the time-dependent CP violation parameters in B0 → K0 S K0 S K0 S decays using 772 × 106 BB̅ pairs collected at the ϒ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. The obtained mixing-induced and direct CP asymmetries are −0.71 ± 0.23 (stat) ± 0.05 (syst) and 0.12 ± 0.16 (stat) 0.05 (syst), respectively. These values are consistent with the Standard Model predictions. The significance of CP violation differs from zero by 2.5 standard deviations.


Magnetic And Electron Transport Properties Of Co2Si Nanomagnets, Balamurugan Balasubramanian, Tom A. George, Priyanka Manchanda, Rabindra Pahari, Ahsan Ullah, Ralph Skomski, David J. Sellmyer Feb 2021

Magnetic And Electron Transport Properties Of Co2Si Nanomagnets, Balamurugan Balasubramanian, Tom A. George, Priyanka Manchanda, Rabindra Pahari, Ahsan Ullah, Ralph Skomski, David J. Sellmyer

Department of Physics and Astronomy: Faculty Publications

Magnetotransport and ferromagnetism in thin films of Co2Si nanoclusters are investigated experimentally and theoretically. The nanoclusters are fabricated by an inert-gas condensation-type cluster-deposition method and have an average size of 11.3 nm. Unlike the bulk Co2Si that exhibits a very weak net magnetic moment only below 10 K, the nanoclusters exhibit room-temperature ferromagnetism with a substantial saturation magnetization. Key features of the system are its closeness to the Stoner transition, magnetic moments induced by spin polarization starting from surface atoms, and nonuniaxial anisotropy associated with the orthorhombic crystal structure of Co2Si. A method is …


Two-Dimensional Antiferroelectric Tunnel Junction, Jun Ding, Ding-Fu Shao, Ming Li, Li-Wei Wen, Evgeny Y. Tsymbal Feb 2021

Two-Dimensional Antiferroelectric Tunnel Junction, Jun Ding, Ding-Fu Shao, Ming Li, Li-Wei Wen, Evgeny Y. Tsymbal

Department of Physics and Astronomy: Faculty Publications

Ferroelectric tunnel junctions (FTJs), which consist of two metal electrodes separated by a thin ferroelectric barrier, have recently aroused significant interest for technological applications as nanoscale resistive switching devices. So far, most existing FTJs have been based on perovskite-oxide barrier layers. The recent discovery of the two-dimensional (2D) van der Waals ferroelectric materials opens a new route to realize tunnel junctions with new functionalities and nm-scale dimensions. Because of the weak coupling between the atomic layers in these materials, the relative dipole alignment between them can be controlled by applied voltage. This allows transitions between ferroelectric and antiferroelectric orderings, resulting …


Ir Finite S-Matrix By Gauge Invariant Dressed States, Hayato Hirai, Sotaro Sugishita Feb 2021

Ir Finite S-Matrix By Gauge Invariant Dressed States, Hayato Hirai, Sotaro Sugishita

Physics and Astronomy Faculty Publications

Dressed states were proposed to define the infrared (IR) finite S-matrix in QED or gravity. We show that the original Kulish-Faddeev dressed states are not enough to cure the IR divergences. To illustrate this problem, we consider QED with background currents (Wilson lines). This theory is exactly solvable but shares the same IR problems as the full QED. We show that naive asymptotic states lead to IR divergences in the S-matrix and are also inconsistent with the asymptotic symmetry, even if we add the original Kulish-Faddeev dressing operators. We then propose new dressed states which are consistent with …


Interaction Of Alpha-Crystallin With Phospholipid Membranes, Laxman Mainali, William J. O'Brien, Raju Timsina Feb 2021

Interaction Of Alpha-Crystallin With Phospholipid Membranes, Laxman Mainali, William J. O'Brien, Raju Timsina

Physics Faculty Publications and Presentations

Purpose/Aim: The amount of membrane-bound α-crystallin increases significantly with age and cataract formation, accompanied by a corresponding decline in the level of α-crystallin in the lens cytoplasm. The purpose of this research is to evaluate the binding affinity of α-crystallin to the phospholipid membranes as well as the physical properties of the membranes after α-crystallin binding.

Materials and Methods: The continuous wave and saturation recovery electron paramagnetic resonance (EPR) methods were used to obtain the information about the binding affinity and the physical properties of the membrane. In this approach, the cholesterol analogue spin label CSL was incorporated in the …


Photoelectric Absorption Cross Section Of Silicon Near The Bandgap From Room Temperature To Sub-Kelvin Temperature, C. Stanford, M. J. Wilson, B. Cabrera, M. Diamond, N. A. Kurinsky, R. A. Moffatt, F. Ponce, B. Von Krosigk, Betty A. Young Feb 2021

Photoelectric Absorption Cross Section Of Silicon Near The Bandgap From Room Temperature To Sub-Kelvin Temperature, C. Stanford, M. J. Wilson, B. Cabrera, M. Diamond, N. A. Kurinsky, R. A. Moffatt, F. Ponce, B. Von Krosigk, Betty A. Young

Physics

The use of cryogenic silicon as a detector medium for dark matter searches is gaining popularity. Many of these searches are highly dependent on the value of the photoelectric absorption cross section of silicon at low temperatures, particularly near the silicon bandgap energy, where the searches are most sensitive to low mass dark matter candidates. While such cross section data have been lacking from the literature, previous dark matter search experiments have attempted to estimate this parameter by extrapolating it from higher temperature data. However, discrepancies in the high temperature data have led to order-of-magnitude differences in the extrapolations. In …