Atomic, Molecular and Optical Physics Commons^™

Applications Of Portable Libs For Actinide Analysis, Ashwin P. Rao, John D. Auxier Ii, Dung Vu, Michael B. Shattan

Faculty Publications

A portable LIBS device was used for rapid elemental impurity analysis of plutonium alloys. This device demonstrates the potential for fast, accurate in-situ chemical analysis and could significantly reduce the fabrication time of plutonium alloys.

Fully Differential Study Of Ionization Of H2 By P Impact Near Velocity Matching, M. Dhital, S. Bastola, A. Silvus, A. Hasan, B. R. Lamichhane, E. Ali, M. F. Ciappina, R. A. Lomsadze, D. Cikota, B. Boggs, Don H. Madison, Michael Schulz

Physics Faculty Research & Creative Works

Fully differential cross sections (FDCS) for ionization in p + H2 collisions in the region of the electron-projectile velocity matching were measured and calculated. The FDCS were found to be very sensitive to the details of the few-body dynamics underlying the reaction.

Triple Differential Cross Sections For Electron Impact Ionization Of Methane At Intermediate Energy, C. Granados, E. Ali, A. Sakaamini, M. Harvey, L. U. Ancarani, A. J. Murray, M. Dogan, C. Ning, J. Colgan, Don H. Madison

Physics Faculty Research & Creative Works

In a joint experimental and theoretical collaboration, triple differential cross sections are presented for electron-impact single ionization of the 1t2 and 2a1 states of CH4 at an incident electron energy of 250 eV. Experimental data from two different laboratories are compared with molecular 3-body distorted wave (M3DW) and generalized Sturmian function (GSF) calculations. Overall, we find a good experiment-experiment, and also a relatively good experiment-theories, agreement. We observe that for the 1t2 state, similarly to ionization of atomic p-states, the peak is sometimes doubled.

New Structures In Fully Differential Cross Sections For Ionization Of He By Proton Impact, M. Dhital, S. Bastola, A. Silvus, A. Hasan, B. R. Lamichhane, E. Ali, M. F. Ciappina, R. A. Lomsadze, Don H. Madison, Michael Schulz

Physics Faculty Research & Creative Works

Fully differential cross sections (FDCS) for ionization in p + He collisions were measured and calculated for several projectile energy losses. The electron angular dependence of the FDCS reveals structures not seen in previous studies.

Energy Dependent Relative Cross Sections In Carbon 1s Photoionization, Michael Schulz, A. Hasan, B. Lamichhane, T. Arthanayaka, M. Dhital, S. Bastola, D. Céolin, C. Nicolas, T. Marchenko, G. Goldsztejn, L. Journel, R. Guillemin, T. X. Carroll, K. J. Børve

Physics Faculty Research & Creative Works

Synopsis We demonstrate that the possibility of monitoring relative photoionization cross sections over a large photon energy range extending to hard x-rays allows studying and disentangling shake processes and intramolecular inelastic scattering effects. An "EXAFS"-type of oscillatory behavior of the relative C 1s cross sections is observed in a wide photon energy range up to 1 keV due to multiple intramolecular elastic scattering of the photoelectron. These effects are also present in solids and constitute a significant part of all elastic and inelastic scattering effects occurring in solids.

Quantum Interference In Monocyclic Molecules: A Novel And Straightforward Phase Wave Model, Zainelabideen Yousif Mijbil

Karbala International Journal of Modern Science

We have proposed by far the simplest model, so-called phase wave model (PWM), to predict quantum interference states in monocyclic molecules. Meanwhile, transmission coefficient calculations were also performed using Green’s function method incorporated with Hückel (Tight Binding) approximation. An impressive agreement has been obtained between the results of the phase wave model and the ones from transmission coefficient calculations for the chosen model systems, namely benzene, cycloheptatriene, cyclooctatetraene, and [10]annulene. PWM represents the phase of wave functions of the incoming electrons by a wave and associates a single wavelength of the phase with five atoms/sites. Hence, the electrical conductance would …

Surface Termination And Schottky-Barrier Formation Of In4Se3(001), Archit Dhingra, Pavlo V. Galiy, Lu Wang, Nataliia S. Vorobeva, Alexey Lipatov, Angel Torres, Taras M. Nenchuk, Simeon J. Gilbert, Alexander Sinitskii, Andrew J. Yost, Wai-Ning Mei, Keisuke Fukutani, Jia Shiang Chen, Peter Dowben

Peter Dowben Publications

The surface termination of In₄Se₃(001) and the interface of this layered trichalcogenide, with Au, was examined using x-ray photoemission spectroscopy. Low energy electron diffraction indicates that the surface is highly crystalline, but suggests an absence of C2v mirror plane symmetry. The surface termination of the In₄Se₃(001 is found, by angle-resolved x-ray photoemission spectroscopy, to be In, which is consistent with the observed Schottky barrier formation found with this n-type semiconductor. Transistor measurements confirm earlier results from photoemission, suggesting that In₄Se₃(001 is an n-type semiconductor, so that Schottky barrier …

Quantum Random Walk Search And Grover's Algorithm - An Introduction And Neutral-Atom Approach, Anna Maria Houk

Physics

In the sub-field of quantum algorithms, physicists and computer scientist take classical computing algorithms and principles and see if there is a more efficient or faster approach implementable on a quantum computer, i.e. a ”quantum advantage”. We take random walks, a widely applicable group of classical algorithms, and move them into the quantum computing paradigm. Additionally, an introduction to a popular quantum search algorithm called Grover’s search is included to guide the reader to the development of a quantum search algorithm using quantum random walks. To close the gap between algorithm and hardware, we will look at using neutral-atom (also …

Perspective: Ferromagnetic Liquids, Robert Streubel, Xubo Liu, Xuefei Wu, Thomas P. Russell

Robert Streubel Papers

Mechanical jamming of nanoparticles at liquid-liquid interfaces has evolved into a versatile approach to structure liquids with solid-state properties. Ferromagnetic liquids obtain their physical and magnetic properties, including a remanent magnetization that distinguishes them from ferrofluids, from the jamming of magnetic nanoparticles assembled at the interface between two distinct liquids to minimize surface tension. This perspective provides an overview of recent progress and discusses future directions, challenges and potential applications of jamming magnetic nanoparticles with regard to 3D nano-magnetism. We address the formation and characterization of curved magnetic geometries, and spin frustration between dipole-coupled nanostructures, and advance our understanding of …

Deep Minima In The Triply Differential Cross Section For Ionization Of Atomic Hydrogen By Electron And Positron Impact, C. M. Demars, S. J. Ward, J. Colgan, S. Amami, Don H. Madison

Physics Faculty Research & Creative Works

We investigate ionization of atomic hydrogen by electron-and positron-impact. We apply the Coulomb-Born (CB1) approximation, various modified CB1 approximations, the three-body distorted wave (3DW) approximation, and the time-dependent close-coupling (TDCC) method to electron-impact ionization of hydrogen. For electron-impact ionization of hydrogen for an incident energy of approximately 76.45 eV, we obtain a deep minimum in the CB1 triply differential cross section (TDCS). However, the TDCC for 74.45 eV and the 3DW for 74.46 eV gave a dip in the TDCS. For positron-hydrogen ionization (breakup) we apply the CB1 approximation and a modified CB1 approximation. We obtain a deep minimum in …

Spectroscopic And Structural Probing Of Excited-State Molecular Dynamics With Time-Resolved Photoelectron Spectroscopy And Ultrafast Electron Diffraction, Yusong Liu, Spencer L. Horton, Jie Yang, J. Pedro F. Nunes, Xiaozhe Shen, Thomas J.A. Wolf, Ruaridh Forbes, Chuan Cheng, Bryan Moore, Martin Centurion, Kareem Hegazy, Renkai Li, Ming Fu Lin, Albert Stolow, Paul Hockett, Tamás Rozgonyi, Philipp Marquetand, Xijie Wang, Thomas Weinacht

Martin Centurion Publications

Pump-probe measurements aim to capture the motion of electrons and nuclei on their natural timescales (femtoseconds to attoseconds) as chemical and physical transformations take place, effectively making "molecular movies"with short light pulses. However, the quantum dynamics of interest are filtered by the coordinate-dependent matrix elements of the chosen experimental observable. Thus, it is only through a combination of experimental measurements and theoretical calculations that one can gain insight into the internal dynamics. Here, we report on a combination of structural (relativistic ultrafast electron diffraction, or UED) and spectroscopic (time-resolved photoelectron spectroscopy, or TRPES) measurements to follow the coupled electronic and …

Generating Entanglement With The Dynamical Lamb Effect, Mirko Amico

Dissertations, Theses, and Capstone Projects

According to quantum field theory, the vacuum is filled with virtual particles which can be turned into real ones under the influence of external perturbations. Phenomena of this kind are commonly referred to as quantum vacuum phenomena. Several quantum vacuum phenomena related to the peculiar nature of the quantum vacuum have been predicted, some of which, such as the Lamb shift and the Casimir effect, have been experimentally found. Other examples of quantum vacuum phenomena include the Unruh effect, the dynamical Casimir effect and the dynamical Lamb effect. The dynamical Lamb effect was first predicted by considering the situation of …

Hyperpolarizability Dispersion Measured For Cs2 Vapor, Rodrigo N. Fernandez, David P. Shelton

Physics & Astronomy Faculty Research

The second hyperpolarizability (��) of carbon disulfide (CS2) is measured by gas-phase electric-field-induced second-harmonic generation for laser wavelengths in the range 765–1064 nm. The observed hyperpolarizability is decomposed into electronic (����) and vibrational (����) contributions, and the dispersion curve for ���� is extrapolated to the static limit, with the result of ����0=12558±93 atomic units =7.83±0.06×10−61C4m4J−3=6.33±0.0×10−36 esu (Taylor series convention). The results of this experiment agree with other recent nonlinear optical measurements and theoretical calculations.

Density Functional Theory Calculations Of Al Doped Hafnia For Different Crystal Symmetry Configurations, Joshua Steier

Seton Hall University Dissertations and Theses (ETDs)

Dogan et al.[1], investigated the causes of ferroelectricity in doped hafnia using ab initio methods. Similarly, we investigated the stability of Al doped hafnia using quantum mechanical methods.

There are many different phases of Hafnia: monoclinic, tetragonal, cubic and orthorhombic. Starting with the monoclinic phase of Hafnia, Hafnia undergoes phase transitions which result in different space groups. The temperature at which the tetragonal phase is induced is 2000 K and cubic phase is induced at 2900 K[1]. Different dielectric constants vary from phase to phase. The average dielectric constants are highest for the cubic and tetragonal phases. In order to …

The Primary Volatile Composition Of Comet C/2015 Er61 (Panstarrs), Aaron Butler

Theses

In the outer edges of the solar system exist two regions: the Kuiper belt and Oort cloud. These two regions have a high amount of icy bodies (comets) orbiting the Sun. Comets located within the Oort cloud and Kuiper belt contain an ancient codex to the solar systems contents, before the formation of our solar system. Presented are near-infrared, high-resolution (λ/Δλ ~40000) data obtained from the immersion-grating echelle spectrograph iSHELL at the 3m NASA Infrared Telescope Facility (IRTF) in Maunakea, Hawaii of the Oort cloud comet C/2015 ER61 (PANSTARRS). Observations took place on April 15 and 17 in 2017 while …

Coherent Captain Mills: The Search For Sterile Neutrinos, Ashley Elliott, Jeramy Gordon, Jonah Greenwood, Rachel Lake, Ryder Moreno, Emily Strawn, Kate Walker

Discovery Day - Prescott

The observation of neutrino oscillations confirms that the active neutrinos (νe, νμ, ντ) are comprised of three mass eigenstates with Δm2 values between 10-3 to 10-5 eV2 . However, a persistent phenomenon has been observed at LSND, MiniBooNE and other shortbaseline experiments (SBE) where Δm2 ~ 1eV2 and is not compatible with the current mixing between mass eigenstates. However, a 4th neutrino, a sterile neutrino (νs) that doesn’t participate in weak interactions could explain the phenomena observed as SBE’s. An experiment has been constructed at TA-53 at Los Alamos National Laboratory to investigate this large Δm2 ~ 1eV2 and determine …

Comparison Of The Vibrational Modes Of Thiolated Gold Nanoparticles Undergoing Core-Conversions Via Raman Spectroscopy, William Gregory Cannella Jr.

Honors Theses

In this project, the vibrational characteristics/vibrational modes are explored via Raman Spectroscopy for thiolated-gold nanoparticles. This class of compounds is also known as gold nanoparticles (AuNPs). They remain of great interest in research areas such as catalysis, gold dependent nanoelectronics, drug delivery, and sensing, due to their unique size-dependent optical, chiroptical, and electronic properties. Vibrational spectroscopy of thiolated gold nanoparticles are oftentimes considered nontrivial as the compounds strongly absorb light in the visible region of the electromagnetic spectrum, are generally considered weak scatterers, and give off large amounts of fluorescence. This combined with their black appearance, susceptibility to localized heating, …

Skyrmion Fluctuations At A First-Order Phase Transition Boundary, V. Esposito, X. Y. Zheng, M. H. Seaberg, S. A. Montoya, B. Holladay, A. H. Reid, R. Streubel, J. C.T. Lee, L. Shen, J. D. Koralek, G. Coslovich, P. Walter, S. Zohar, V. Thampy, M. F. Lin, P. Hart, K. Nakahara, P. Fischer, W. Colocho, A. Lutman, F. J. Decker, S. K. Sinha, E. E. Fullerton, S. D. Kevan, S. Roy, M. Dunne, J. J. Turner

Robert Streubel Papers

Magnetic skyrmions are topologically protected spin textures with promising prospects for applications in data storage. They can form a lattice state due to competing magnetic interactions and are commonly found in a small region of the temperature - magnetic field phase diagram. Recent work has demonstrated that these magnetic quasi-particles fluctuate at the μeV energy scale. Here, we use a coherent x-ray correlation method at an x-ray free-electron laser to investigate these fluctuations in a magnetic phase coexistence region near a first-order transition boundary where fluctuations are not expected to play a major role. Surprisingly, we find that the relaxation …

Optically Pumped Spin Polarization As A Probe Of Many-Body Thermalization, Daniela Pagliero, Pablo R. Zangara, Jacob Henshaw, Ashok Ajoy, Rodolfo H. Acosta, Jeffrey A. Reimer, Alexander Pines, Carlos A. Meriles

Publications and Research

Disorder and many body interactions are known to impact transport and thermalization in competing ways, with the dominance of one or the other giving rise to fundamentally different dynamical phases. Here we investigate the spin diffusion dynamics of ¹³C in diamond, which we dynamically polarize at room temperature via optical spin pumping of engineered color centers. We focus on low-abundance, strongly hyperfine-coupled nuclei, whose role in the polarization transport we expose through the integrated impact of variable radio-frequency excitation on the observable bulk ¹³C magnetic resonance signal. Unexpectedly, we find good thermal contact throughout the nuclear spin bath, …

An Overview Of Lasers And Their Applications, Luis Cristian Giovanni Guerrero

Physics

This paper is an overview of lasers and their applications. The fundamentals of laser operation are covered as well as the various applications of advanced laser systems. The primary focus is to highlight some of the technological advancements made possible by lasers in the last half-century.