Nanostructural Origin Of Semiconductivity And Large Magnetoresistance In Epitaxial Nico2O4/Al2O3 Thin Films,
2018
Hebei Normal University
Nanostructural Origin Of Semiconductivity And Large Magnetoresistance In Epitaxial Nico2O4/Al2O3 Thin Films, Congmian Zhen, Xiaozhe Zhang, Wengang Wei, Wenzhe Guo, Ankit Pant, Xiaoshan Xu, Jian Shen, Li Ma, Denglu Hou
Xiaoshan Xu Papers
Despite low resistivity (~1 mΩ cm), metallic electrical transport has not been commonly observed in inverse spinel NiCo2O4, except in certain epitaxial thin films. Previous studies have stressed the effect of valence mixing and the degree of spinel inversion on the electrical conduction of NiCo2O4 films. In this work, we studied the effect of nanostructural disorder by comparing the NiCo2O4 epitaxial films grown on MgAl2O4 (1 1 1) and on Al2O3 (0 0 1) substrates. Although the optimal growth conditions are similar for the …
Influence Of Basis-Set Size On The X2Σ+1/2, A2Π1/2, A2Π3/2, And B2Σ1/2 Potential-Energy Curves, A2Π3/2 2 Vibrational Energies, And D1 And D2 Line Shapes Of Rb+He,
2018
Wright State University
Influence Of Basis-Set Size On The X2Σ+1/2, A2Π1/2, A2Π3/2, And B2Σ1/2 Potential-Energy Curves, A2Π3/2 2 Vibrational Energies, And D1 And D2 Line Shapes Of Rb+He, L. Aaron Blank, Amit R. Sharma, David E. Weeks
Faculty Publications
The X 2 Σ + 1 / 2 , A 2 Π 1 / 2 , A 2 Π 3 / 2 , and B 2 Σ + 1 / 2 potential-energy curves for Rb+He are computed at the spin-orbit multireference configuration interaction level of theory using a hierarchy of Gaussian basis sets at the double-zeta (DZ), triple-zeta (TZ), and quadruple-zeta (QZ) levels of valence quality. Counterpoise and Davidson-Silver corrections are employed to remove basis-set superposition error and ameliorate size-consistency error. An extrapolation is performed to obtain a final set of potential-energy curves in the complete basis-set (CBS) limit. This …
Probing Scattering Phases Via Two-Center Interferences In Collisions Of He²⁺ On Co,
2018
Missouri University of Science and Technology
Probing Scattering Phases Via Two-Center Interferences In Collisions Of He²⁺ On Co, Y. Gao, S. F. Zhang, X. L. Zhu, D. L. Guo, Michael Schulz, A. B. Voitkiv, D. M. Zhao, B. Hai, M. Zhang, R. T. Zhang, W. T. Feng, S. Yan, H. B. Wang, Z. K. Huang
Physics Faculty Research & Creative Works
Phases of quantum transition amplitudes contain very important information about physical processes. However, as a rule, they may not be accessed experimentally. This is, in particular, the case when collisions of ions and atoms are studied. In this rapid communication, we explore double electron capture in collisions of α particles with CO molecules. Regarding the atomic cores of the molecule as two "slits," we show that atomic "double slit" interference can be exploited to experimentally extract information about phases of the projectile scattering on the cores.
Studies Of Light Generation With Four-Wave Mixing In A Cold Atomic Ensemble,
2018
University of New Mexico - Main Campus
Studies Of Light Generation With Four-Wave Mixing In A Cold Atomic Ensemble, Andrew Ferdinand
Physics & Astronomy ETDs
Correlated light generated from atomic ensembles can have a central role in prominent quantum information protocols, such as long-distance quantum communication. Here we present our studies on three topics involving the generation of correlated light with four-wave mixing (FWM) in a cold atomic ensemble for applications in quantum communications with high capacity. We experimentally investigate the generation of light with seeded FWM in cold cesium atoms and the time correlations of photon pairs generated with spontaneous FWM. We theoretically investigate the correlations in orbital angular momentum of photon pairs generated with spontaneous FWM for a range of experimental geometries. These …
Time-Resolved Electron (E,2E) Momentum Spectroscopy: Application To Laser-Driven Electron
Population Transfer In Atoms,
2018
University of Nebraska - Lincoln
Time-Resolved Electron (E,2E) Momentum Spectroscopy: Application To Laser-Driven Electron Population Transfer In Atoms, Hua-Chieh Shao, Anthony F. Starace
Anthony F. Starace Publications
Owing to its ability to provide unique information on electron dynamics, time-resolved electron momentum spectroscopy (EMS) is used to study theoretically a laser-driven electronic motion in atoms. Specifically, a chirped laser pulse is used to adiabatically transfer the populations of lithium atoms from the ground state to the first excited state. During this process, impact ionization near the Bethe ridge by time-delayed ultrashort, high-energy electron pulses is used to image the instantaneous momentum density of this electronic population transfer. Simulations with 100 fs and 1 fs pulse durations demonstrate the capability of EMS to image the time-varying momentum density, including …
Pentaquarks With Hidden Charm As Hadroquarkonia,
2018
University of Kentucky
Pentaquarks With Hidden Charm As Hadroquarkonia, Michael I. Eides, Victor Yu. Petrov, Maxim V. Polyakov
Physics and Astronomy Faculty Publications
We consider hidden charm pentaquarks as hadroquarkonium states in a QCD inspired approach. Pentaquarks arise naturally as bound states of quarkonia excitations and ordinary baryons. The LHCb Pc(4450) pentaquark is interpreted as a ψ′-nucleon bound state with spin-parity J P =3/2−. The partial decay width Γ(Pc(4450) → J / ψ + N) ≈ 11 MeV is calculated and turned out to be in agreement with the experimental data for Pc(4450). The Pc(4450) pentaquark is predicted to be a member of one of the two almost degenerate …
Structure And Magnetism Of Mn5ge3 Nanoparticles,
2018
University of Delaware
Structure And Magnetism Of Mn5ge3 Nanoparticles, Onur Tosun, Mohammed Salehi-Fashami, Balamurugan Balasubramanian, Ralph Skomski, David J. Sellmyer, George C. Hadjipanayis
Nebraska Center for Materials and Nanoscience: Faculty Publications
In this work, we investigated the magnetic and structural properties of isolated Mn5Ge3 nanoparticles prepared by the cluster-beam deposition technique. Particles with sizes between 7.2 and 12.6 nm were produced by varying the argon pressure and power in the cluster gun. X-ray diffraction (XRD)and selected area diffraction (SAD) measurements show that the nanoparticles crystallize in the hexagonal Mn5Si3-type crystal structure, which is also the structure of bulk Mn5Ge3. The temperature dependence of the magnetization shows that the as-made particles are ferromagnetic at room temperature and have slightly different Curie …
Structural, Magnetic, And Electron-Transport Properties Of Epitaxial Mn2Ptsn Films,
2018
University of Nebraska-Lincoln
Structural, Magnetic, And Electron-Transport Properties Of Epitaxial Mn2Ptsn Films, Y. Jin, Shah R. Valloppilly, Parashu Kharel, Jace Waybright, Pavel V. Lukashev, Xingzhong Li, David J. Sellmyer
Nebraska Center for Materials and Nanoscience: Faculty Publications
The growth of new magnetic materials on suitable insulating substrates is an important part of the development of spin-electronics devices for memory or information processing. Epitaxial thin films of Mn2PtSn were grown on a MgO [001] substrate by magnetron co-sputtering of the constituents. Structural, magnetic, and electron-transport properties were investigated. The epitaxial Mn2PtSn film has an inverse tetragonal structure with the c-axis aligned in the plane of the MgO substrate. The lattice constants determined using XRD and TEM analysis are c=6.124Å and a=b=4.505Å. The orientation of Mn2PtSn c-axis which …
Multi-Walled Carbon Nanotube-Coated Spiral Coils For Loss Reduction In Wireless Power
Transfer Systems,
2018
University of Nebraska-Lincoln
Multi-Walled Carbon Nanotube-Coated Spiral Coils For Loss Reduction In Wireless Power Transfer Systems, Kamran Keramatnejad, Dawei Li, Hossein Rabiee Golgir, Loic Constantin, Xi Huang, Qiming Zou, Jean-Francois Silvain, Stephen Ducharme, Yongfeng Lu
Stephen Ducharme Publications
Realization of high efficiency and long transmission range in high-frequency wireless power transfer (WPT) systems has always been hindered by the increased resistance due to the eddy current loss occurring in the inductive coils. In this study, multi-walled carbon nanotube-coated copper (MWCNT-Cu) coils are successfully introduced to address this limitation by implementing the frequency-inert MWCNT channels along with using their high-surface areas to realize the electromagnetic shielding of the Cu substrate through multiple reflection mechanisms. At a frequency of 15 MHz, the resistance of the individual MWCNT-Cu coil was reduced to less than 40% of its original value for primitive …
X-Ray Spectroscopy Of Nio And Nanodiamond At Ssrl,
2018
Illinois State University
X-Ray Spectroscopy Of Nio And Nanodiamond At Ssrl, Jackson Earl
STAR Program Research Presentations
The first aspect of this research project focuses on investigating the surface chemistry of high pressure high temperature (HPHT) nanodiamond by using X-ray spectroscopy techniques at the Stanford Synchrotron Radiation Lightsource (SSRL). HPHT nanodiamond is being examined as a biosensing tool for electric field detection based on the fluorescent nitrogen vacancy center hosted within diamond. With use of the transition edge spectrometer (TES), a state-of-the-art X-ray fluorescence detector, we are able to probe the surface and bulk properties of diamond. Preliminary work using density functional theory (DFT) has been done, offering insight into ground state energies and electronic structure. DFT …
A Brief Review Of Ferroelectric Control Of Magnetoresistance In Organic
Spin Valves,
2018
University of Nebraska-Lincoln
A Brief Review Of Ferroelectric Control Of Magnetoresistance In Organic Spin Valves, Xiaoshan Xu
Xiaoshan Xu Papers
Magnetoelectric coupling has been a trending research topic in both organic and inorganic materials and hybrids. The concept of controlling magnetism using an electric field is particularly appealing in energy efficient applications. In this spirit, ferroelectricity has been introduced to organic spin valves to manipulate the magneto transport, where the spin transport through the ferromagnet/organic spacer interfaces (spinterface) are under intensive study. The ferroelectric materials in the organic spin valves provide a knob to vary the interfacial energy alignment and the interfacial crystal structures, both are critical for the spin transport. In this review, we introduce the recent efforts of …
Laser-Induced Electron Emission From Au Nanowires: A Probe For Orthogonal Polarizations,
2018
University of Nebraska-Lincoln
Laser-Induced Electron Emission From Au Nanowires: A Probe For Orthogonal Polarizations, Eric R. Jones, Wayne Cheng-Wei Huang, Gobind Basnet, Bret N. Flanders, Herman Batelaan
Department of Physics and Astronomy: Faculty Publications
Photoelectron field emission, induced by femtosecond laser pulses focused on metallic nanotips, provides spatially coherent and temporally short electron pulses. The properties of the photoelectron yield give insight into both the material properties of the nanostructure and the exciting laser focus. Ultralong nanoribbons, grown as a single crystal attached to a metallic taper, are sources of electron field emission that have not yet been characterized. In this report, photoemission from gold nanoribbon samples is studied and compared to emission from tungsten and gold tips. We observe that the emission from sharp tips generally depends on one transverse component of the …
Resonant Anisotropic Emission In Rabbitt Spectroscopy,
2018
University of Central Florida
Resonant Anisotropic Emission In Rabbitt Spectroscopy, Bejan M. Ghomashi
Honors Undergraduate Theses
A variant of RABBITT pump-probe spectroscopy in which the attosecond pulse train comprises both even and odd harmonics of the fundamental IR probe frequency is explored to measure time-resolved photoelectron emission in systems that exhibit autoionizing states. It is shown that the group delay of both one-photon and two-photon resonant transitions is directly encoded in the energy-resolved photoelectron anisotropy as a function of the pump-probe time-delay. This principle is illustrated for a 1D model with symmetric zero-range potentials that supports both bound states and shape-resonances. The model is studied using both perturbation theory and solving the time-dependent Schodinger equation on …
The Promise Of Piezoelectric Polymers,
2018
California State University San Bernardino
The Promise Of Piezoelectric Polymers, Timothy D. Usher, Kimberley R. Cousins, Renwu Zhang, Stephen Ducharme
Stephen Ducharme Publications
Recent advances provide new opportunities in the field of polymer piezoelectric materials. Piezoelectric materials provide unique insights to the fundamental understanding of the solid state. In addition, piezoelectric materials have a wide range of applications, representing billions of dollars of commercial applications. However, inorganic piezoelectric materials have limitations that polymer ferroelectric materials can overcome, if certain challenges can be addressed. This mini-review is a practical summary of the current research and future directions in the investigation and application of piezoelectric materials with an emphasis on polymeric piezoelectric materials. We will assume that the reader is well versed in the subject …
Towards A Strong Spin–Orbit Coupling Magnetoelectric Transistor,
2018
University of Nebraska - Lincoln
Towards A Strong Spin–Orbit Coupling Magnetoelectric Transistor, Peter Dowben, Christian Binek, Kai Zhang, Lu Wang, Wai-Ning Mei, Jonathan P. Bird, Uttam Singisetti, Xia Hong, Kang L. Wang, Dmitri Nikonov
Peter Dowben Publications
Here, we outline magnetoelectric (ME) device concepts based on the voltage control of the interface magnetism of an ME antiferromagnet gate dielectric formed on a very thin semiconductor channel with large spin–orbit coupling (SOC). The emphasis of the ME spin field-effect transistors (ME spin FET) is on an antiferromagnet spin–orbit read logic device and a ME spin-FET multiplexer. Both spin-FET schemes exploit the strong SOC in the semiconducting channel materials but remain dependent on the voltage-induced switching of an ME, so that the switching time is limited only by the switching dynamics of the ME. The induced exchange field spin …
Xuv-Assisted High-Order-Harmonic-Generation Spectroscopy,
2018
Voronezh State University
Xuv-Assisted High-Order-Harmonic-Generation Spectroscopy, T. S. Sarantseva, M. V. Frolov, N. L. Manakov, A. A. Silaev, N. V. Vvedenskii, Anthony F. Starace
Anthony F. Starace Publications
Using the analytic time-dependent effective range theory, we study two-color high-order harmonic generation (HHG) involving a weak extreme ultraviolet (XUV) pulse and an intense infrared laser field. Our analysis shows that XUV-assisted HHG spectra contain multiple additional plateau structures originating from absorption of one or more XUV photons at the photorecombination step of HHG. We show also that the HHG rate corresponding to the nth plateau can be presented in a factorized form involving the XUV-assisted (multiphoton) photorecombination cross section (PRCS) corresponding to absorption of n XUV photons of energy Ω and emission of a harmonic of energy Ωh …
Analysis Of The Red And Green Optical Absorption Spectrum Of Gas Phase Ammonia,
2018
Old Dominion University
Analysis Of The Red And Green Optical Absorption Spectrum Of Gas Phase Ammonia, Nikolai F. Zobov, Phillip A. Coles, Roman I. Ovsyannikov, Aleksandra A. Kyuberis, Robert J. Hargreaves, Peter F. Bernath, Jonathan Tennyson, Sergei N. Yurchenko, Oleg L. Polyansky
Chemistry & Biochemistry Faculty Publications
Room temperature NH3 absorption spectra recorded at the Kitt Peak National Solar Observatory in 1980 are analyzed. The spectra cover two regions in the visible: 15,200 - 15,700 cm-1 and 17,950 - 18,250 cm-1. These high overtone rotation-vibration spectra are analyzed using both combination differences and variational line lists. Two variational line lists were computed using the TROVE nuclear motion program: one is based on an ab initio potential energy surface (PES) while the other used a semi-empirical PES. Ab initio dipole moment surfaces are used in both cases. 95 energy levels with J = 1 …
Novel Faraday Rotation Effects Observed In Ultra-Thin Iron Garnet Films,
2018
Michigan Technological University
Novel Faraday Rotation Effects Observed In Ultra-Thin Iron Garnet Films, Brandon Blasiola
Dissertations, Master's Theses and Master's Reports
Recent work performed by A. Chakravarty and M. Levy showed experimentally a dramatic increase in the specific Faraday Rotation (FR) of the iron garnet Bi0.8Lu0.2Gd2Fe5O12. A theoretical model, based purely on classical electrodynamics, attempting to explain this behavior was developed by colleagues in Russia that not only confirmed the asymptotic increase in the specific FR at sub-50nm film thicknesses but also suggested that the specific FR should exhibit significant fluctuations at sub-500 nm film thicknesses. The original data points were widespread with steps of 50 nm or more between data …
Block-Copolymer Assisted Fabrication Of Anisotropic Plasmonic Nanostructures,
2018
Missouri State University
Block-Copolymer Assisted Fabrication Of Anisotropic Plasmonic Nanostructures, Calbi J. Gunder
Graduate Theses/Dissertations
The anisotropic nanostructures of noble metals are of great interest for plasmonic applications due to the possibility of tuning the localized surface plasmon resonance (LSPR) across the UV-VIS-NIR without sacrificing the linewidth as well as to achieve larger local field enhancement. Here, we report a simple and promising fabrication method of anisotropic gold nanostructures film using polystyrene-b-2vinylpyridine (PS-b-P2VP) block copolymers (BCP) as a template. In this approach, PS-b-P2VP spherical micelles were first synthesized as a template followed by selective deposition of Au precursor inside P2VP core of the micelles using ethanol solution of Au salt. Subsequently, heat treatment of the …
Comparison Of Various Mean Field Formulations For Retrieving Refractive Indices Of Aerosol Particles Containing Inclusions,
2018
University of Central Arkansas
Comparison Of Various Mean Field Formulations For Retrieving Refractive Indices Of Aerosol Particles Containing Inclusions, Kristin S. Dooley, Jessica Deyoung
Journal of the Arkansas Academy of Science
Application of effective medium approximation (EMA) methods to two-component systems are presented. Systems studied are composed of water, sulfate, soot, and dust as these are commonly encountered atmospheric aerosol components. Atmospheric models often employ EMAs to include internally mixed aerosols without the computational burden of exact theory. In the current work, several types of mixing rules (Maxwell-Garnet, Bruggeman, and coherent potential approximation) have been applied to various two-component internally mixed particles at 550 nm using volume fractions of the minor component below 0.1. As expected, results show that the formulations tested produce very similar effective refractive indices indicating that electric …
