Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Molecules (5)
- Particle detectors (5)
- Fully differential cross sections (4)
- Helium (4)
- Differential cross section (3)
-
- Electrons (3)
- Experimental data (3)
- Impact ionization (3)
- Ionization (3)
- Nuclear Charge Numbers (3)
- Particle Detectors (3)
- Photons (3)
- Self-energy Corrections (3)
- Strong Field (3)
- Superconductivity (3)
- Aligned Molecules (2)
- Atomic physics (2)
- Bound Electrons (2)
- Charge transfer (2)
- Computer simulation (2)
- Distorted-wave models (2)
- Double ionization (2)
- Ejected electrons (2)
- Electron G-factor (2)
- Electron Models (2)
- Electron impact (2)
- Electron-impact ionization (2)
- Free electron lasers (2)
- Gravitational effects (2)
- Gravity waves (2)
Articles 1 - 30 of 52
Full-Text Articles in Physics
Reaction Dynamics In Double Ionization Of Helium By Electron Impact, Marcelo F. Ciappina, Michael Schulz, Tom Kirchner
Reaction Dynamics In Double Ionization Of Helium By Electron Impact, Marcelo F. Ciappina, Michael Schulz, Tom Kirchner
Physics Faculty Research & Creative Works
We present theoretical fully differential cross sections (FDCS) for double ionization of helium by 500 eV and 2 keV electron impact. Contributions from various reaction mechanisms to the FDCS were calculated separately and compared to experimental data. Our theoretical methods are based on the first Born approximation. Higher-order effects are incorporated using the Monte Carlo event generator technique. Earlier, we successfully applied this approach to double ionization by ion impact, and in the work reported here it is extended to electron impact. We demonstrate that at 500 eV impact energy, double ionization is dominated by higher-order mechanisms. Even at 2 …
Large Group Delay In A Microwave Metamaterial Analog Of Electromagnetically Induced Transparency, Lei Zhang, Philippe Tassin, Thomas Koschny, Cihan Kurter, Steven M. Anlage, C. M. Soukoulis
Large Group Delay In A Microwave Metamaterial Analog Of Electromagnetically Induced Transparency, Lei Zhang, Philippe Tassin, Thomas Koschny, Cihan Kurter, Steven M. Anlage, C. M. Soukoulis
Physics Faculty Research & Creative Works
We report on our experimental work concerning a planar metamaterial exhibiting classical electromagnetically induced transparency (EIT). Using a structure with two mirrored split-ring resonators as the dark element and a cut wire as the radiative element, we demonstrate that an EIT-like resonance can be achieved without breaking the symmetry of the structure. The mirror symmetry of the metamaterial's structural element results in a selection rule inhibiting magnetic dipole radiation for the dark element, and the increased quality factor leads to low absorption (<10%) and large group index (of the order of 30).
Direct Observation Of Spin-Polarized Surface States In The Parent Compound Of A Topological Insulator Using Spin- And Angle-Resolved Photoemission Spectroscopy In A Mott-Polarimetry Mode, David Hsieh, Lewis Andrew Wray, Dong Qian, Yuqi Xia, Jan Hugo Dil, Fabian Meier, Luc Patthey, Jurg Osterwalder, Gustav Bihlmayer, Yew San Hor, Robert Joseph Cava, Md Zahid Hasan
Direct Observation Of Spin-Polarized Surface States In The Parent Compound Of A Topological Insulator Using Spin- And Angle-Resolved Photoemission Spectroscopy In A Mott-Polarimetry Mode, David Hsieh, Lewis Andrew Wray, Dong Qian, Yuqi Xia, Jan Hugo Dil, Fabian Meier, Luc Patthey, Jurg Osterwalder, Gustav Bihlmayer, Yew San Hor, Robert Joseph Cava, Md Zahid Hasan
Physics Faculty Research & Creative Works
We report high-resolution spin-resolved photoemission spectroscopy (spin-ARPES) measurements on the parent compound Sb of the recently discovered three-dimensional topological insulator Bi1-xSbx (Hsieh et al 2008 Nature 452 970, Hsieh et al 2009 Science 323 919). By modulating the incident photon energy, we are able to map both the bulk and the (111) surface band structure, from which we directly demonstrate that the surface bands are spin polarized by the spin-orbit interaction and connect the bulk valence and conduction bands in a topologically non-trivial way. A unique asymmetric Dirac surface state gives rise to a k-splitting of its …
Search For Gravitational Waves From Compact Binary Coalescence In Ligo And Virgo Data From S5 And Vsr1, J. Abadie, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Search For Gravitational Waves From Compact Binary Coalescence In Ligo And Virgo Data From S5 And Vsr1, J. Abadie, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We report the results of the first search for gravitational waves from compact binary coalescence using data from the Laser Interferometer Gravitational-Wave Observatory and Virgo detectors. Five months of data were collected during the Laser Interferometer Gravitational-Wave Observatory's S5 and Virgo's VSR1 science runs. The search focused on signals from binary mergers with a total mass between 2 and 35M⊙. No gravitational waves are identified. The cumulative 90%-confidence upper limits on the rate of compact binary coalescence are calculated for nonspinning binary neutron stars, black hole-neutron star systems, and binary black holes to be 8.7 x 10- …
Stability And Charge Transfer Levels Of Extrinsic Defects In Linbo₃, Haixuan Xu, Aleksandr V. Chernatynskiy, Donghwa Lee, Susan Sinnott, Venkatraman Gopalan, Volkmar Dierolf, Simon R. Phillpot
Stability And Charge Transfer Levels Of Extrinsic Defects In Linbo₃, Haixuan Xu, Aleksandr V. Chernatynskiy, Donghwa Lee, Susan Sinnott, Venkatraman Gopalan, Volkmar Dierolf, Simon R. Phillpot
Physics Faculty Research & Creative Works
The technologically important incorporation of extrinsic defects (Mg2+, Fe2+, Fe3+, Er3+, and Nd3+) in LiNbO3 is investigated using density-functional theory combined with thermodynamic calculations. Defect energies, the charge compensation mechanisms, and charge transfer levels, are determined for congruent and stoichiometric compositions. In general, under congruent (Nb2O5-rich) conditions impurities occupy lithium sites, compensated by lithium vacancies. Under stoichiometric (Li2O-rich) conditions, impurities occupy both lithium and niobium sites. The effects of the concentration of Mg on the dominant defect and site occupancy are analyzed. In …
Anderson Localization As Position-Dependent Diffusion In Disordered Waveguides, Ben Payne, Alexey Yamilov, Sergey E. Skipetrov
Anderson Localization As Position-Dependent Diffusion In Disordered Waveguides, Ben Payne, Alexey Yamilov, Sergey E. Skipetrov
Physics Faculty Research & Creative Works
We show that the recently developed self-consistent theory of Anderson localization with a position-dependent diffusion coefficient is in quantitative agreement with the supersymmetry approach up to terms of the order of 1 / g20 (with g0 the dimensionless conductance in the absence of interference effects) and with large-scale ab initio simulations of the classical wave transport in disordered waveguides, at least for g0 ≥ 0.5. In the latter case, agreement is found even in the presence of absorption. Our numerical results confirm that in open disordered media, the onset of Anderson localization can be viewed as …
Evaluation Of Computational Techniques For Solving The Boltzmann Transport Equation For Lattice Thermal Conductivity Calculations, Aleksandr V. Chernatynskiy, Simon R. Phillpot
Evaluation Of Computational Techniques For Solving The Boltzmann Transport Equation For Lattice Thermal Conductivity Calculations, Aleksandr V. Chernatynskiy, Simon R. Phillpot
Physics Faculty Research & Creative Works
Three methods for computing thermal conductivity from lattice dynamics (the iterative method, the variational method, and the relaxation-time approximation) are compared for the prototypical case of solid argon. The iterative method is found to produce results in close agreement with Green-Kubo molecular-dynamics simulations, a formally correct method for computing thermal conductivity. The variational method and relaxation-time approximation are found to underestimate the thermal conductivity. The relationship among the methods is established; a combination of the iterative and variational methods is found to have a fastest convergence. Formal convergence of the iterative method is demonstrated and a simple mixing rule is …
Erratum: Determination Of Structure Parameters In Strong-Field Tunneling Ionization Theory Of Molecules (Physical Review A (2010) 81 (033423)), Song-Feng Zhao, Cheng Jin, Anh-Thu Le, T. F. Jiang, C. D. Lin
Erratum: Determination Of Structure Parameters In Strong-Field Tunneling Ionization Theory Of Molecules (Physical Review A (2010) 81 (033423)), Song-Feng Zhao, Cheng Jin, Anh-Thu Le, T. F. Jiang, C. D. Lin
Physics Faculty Research & Creative Works
There are several errors in Tables V and VI of our article. In Table V, the C2m of the HOMO-1 (1π) of CO molecule should be 0.014. In Table VI, the binding energies of 2pπg and 2pπu of H₂⁺ should be 0.2267 and 0.4288, respectively.
Dynamical Conductivity At The Dirty Superconductor-Metal Quantum Phase Transition, Adrian Del Maestro, Bernd Rosenow, Jose A. Hoyos, Thomas Vojta
Dynamical Conductivity At The Dirty Superconductor-Metal Quantum Phase Transition, Adrian Del Maestro, Bernd Rosenow, Jose A. Hoyos, Thomas Vojta
Physics Faculty Research & Creative Works
We study the transport properties of ultrathin disordered nanowires in the neighborhood of the superconductor-metal quantum phase transition. To this end we combine numerical calculations with analytical strong-disorder renormalization group results. The quantum critical conductivity at zero temperature diverges logarithmically as a function of frequency. In the metallic phase, it obeys activated scaling associated with an infinite-randomness quantum critical point. We extend the scaling theory to higher dimensions and discuss implications for experiments.
Relation Between Transmission And Energy Stored In Random Media With Gain, Ben Payne, Jonathan Andreasen, Hui Cao, Alexey Yamilov
Relation Between Transmission And Energy Stored In Random Media With Gain, Ben Payne, Jonathan Andreasen, Hui Cao, Alexey Yamilov
Physics Faculty Research & Creative Works
In this work, we investigate a possibility of using the ratio between optical transmission, T, and energy stored inside the system, E, as a quantitative measure of the enhanced mesoscopic corrections to diffusive transport of light through a random medium with gain. We obtain an expression for T/E as a function of amplification strength in the diffusive approximation and show that it does not a have tendency to diverge when the threshold for random lasing is approached, as both T and E do. Furthermore, we find that a change in T/E signifies a change in the electric field distribution inside …
Effect Of An Improved Molecular Potential On Strong-Field Tunneling Ionization Of Molecules, Song-Feng Zhao, Cheng Jin, Anh-Thu Le, C. D. Lin
Effect Of An Improved Molecular Potential On Strong-Field Tunneling Ionization Of Molecules, Song-Feng Zhao, Cheng Jin, Anh-Thu Le, C. D. Lin
Physics Faculty Research & Creative Works
We study the effect of one-electron model potentials on the tunneling ionization rates of molecules in strong fields. By including electron correlation using the modified Leeuwen-Baerends (LB α) model, the binding energies of outer shells of molecules are significantly improved. However, we show that the tunneling ionization rates from the LB α do not differ much from the earlier calculations [Phys. Rev. A 81, 033423 (2010)], in which the local correlation potential was neglected.
Tracing Multiple Scattering Patterns In Absolute (E, 2e) Cross Sections For H₂ And He Over A 4Π Solid Angle, Xueguang Ren, Arne Senftleben, Thomas Pflüger, Alexander Dorn, James Colgan, Michael S. Pindzola, Ola A. Al-Hagan, Don H. Madison, Igor Bray, Dmitry V. Fursa, Joachim Hermann Ullrich
Tracing Multiple Scattering Patterns In Absolute (E, 2e) Cross Sections For H₂ And He Over A 4Π Solid Angle, Xueguang Ren, Arne Senftleben, Thomas Pflüger, Alexander Dorn, James Colgan, Michael S. Pindzola, Ola A. Al-Hagan, Don H. Madison, Igor Bray, Dmitry V. Fursa, Joachim Hermann Ullrich
Physics Faculty Research & Creative Works
Absolutely normalized (e,2e) measurements for H2 and He covering the full solid angle of one ejected electron are presented for 16 eV sum energy of both final state continuum electrons. For both targets rich cross-section structures in addition to the binary and recoil lobes are identified and studied as a function of the fixed electron's emission angle and the energy sharing among both electrons. For H2 their behavior is consistent with multiple scattering of the projectile as discussed before. For He the binary and recoil lobes are significantly larger than for H2 and partly cover the multiple …
Baryon Acoustic Oscillations In 2d: Modeling Redshift-Space Power Spectrum From Perturbation Theory, Atsushi Taruya, Takahiro Nishimichi, Shun Saito
Baryon Acoustic Oscillations In 2d: Modeling Redshift-Space Power Spectrum From Perturbation Theory, Atsushi Taruya, Takahiro Nishimichi, Shun Saito
Physics Faculty Research & Creative Works
We present an improved prescription for the matter power spectrum in redshift space taking proper account of both nonlinear gravitational clustering and redshift distortion, which are of particular importance for accurately modeling baryon acoustic oscillations (BAOs). Contrary to the models of redshift distortion phenomenologically introduced but frequently used in the literature, the new model includes the corrections arising from the nonlinear coupling between the density and velocity fields associated with two competitive effects of redshift distortion, i.e., Kaiser and Finger-of-God effects. Based on the improved treatment of perturbation theory for gravitational clustering, we compare our model predictions with the monopole …
First Search For Gravitational Waves From The Youngest Known Neutron Star, J. Abadie, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
First Search For Gravitational Waves From The Youngest Known Neutron Star, J. Abadie, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.
Physics Faculty Research & Creative Works
We present a search for periodic gravitational waves from the neutron star in the supernova remnant Cassiopeia A. The search coherently analyzes data in a 12 day interval taken from the fifth science run of the Laser Interferometer Gravitational-Wave Observatory. It searches gravitational-wave frequencies from 100 to 300 Hz and covers a wide range of first and second frequency derivatives appropriate for the age of the remnant and for different spin-down mechanisms. No gravitational-wave signal was detected. Within the range of search frequencies, we set 95% confidence upper limits of (0.7-1.2) x 10-24 on the intrinsic gravitational-wave strain, (0.4-4) …
Dynamical (E, 2e) Studies Using Tetrahydrofuran As A Dna Analog, Christopher J. Colyer, Susan M. Bellm, B. Lohmann, G. Friedrich Hanne, Ola A. Al-Hagan, Don H. Madison, Chuangang Ning
Dynamical (E, 2e) Studies Using Tetrahydrofuran As A Dna Analog, Christopher J. Colyer, Susan M. Bellm, B. Lohmann, G. Friedrich Hanne, Ola A. Al-Hagan, Don H. Madison, Chuangang Ning
Physics Faculty Research & Creative Works
Triple differential cross sections for the electron-impact ionization of the outer valence orbital of tetrahydrofuran have been measured using the (e, 2e) technique. The measurements have been performed with coplanar asymmetric kinematics, at an incident electron energy of 250 eV and at an ejected electron energy of 10 eV, over a range of momentum transfers. The experimental results are compared with theoretical calculations carried out using the molecular three-body distorted wave model. The results obtained are important for gaining an understanding of electron driven processes at a molecular level and for modeling energy deposition in living tissue.
Self-Imaging Of Molecules From Diffraction Spectra By Laser-Induced Rescattering Electrons, Junliang Xu, Zhangjin Chen, Anh-Thu Le, C. D. Lin
Self-Imaging Of Molecules From Diffraction Spectra By Laser-Induced Rescattering Electrons, Junliang Xu, Zhangjin Chen, Anh-Thu Le, C. D. Lin
Physics Faculty Research & Creative Works
We study high-energy angle-resolved photoelectron spectra of molecules in strong fields. In an oscillating laser electric field, electrons released earlier in the pulse may return to recollide with the target ion, in a process similar to scattering by laboratory prepared electrons. If midinfrared lasers are used, we show that the images generated by the returning electrons are similar to images observed in typical gas-phase electron diffraction (GED). These spectra can be used to retrieve the positions of atoms in a molecule as in GED. Since infrared laser pulses of durations of a few femtoseconds are already available today, the study …
Influence Of Ambient Temperature On The Pm Emissions From A Gas Turbine Engine, Donald E. Hagen, Prem Lobo, Philip D. Whitefield, Max B. Trueblood
Influence Of Ambient Temperature On The Pm Emissions From A Gas Turbine Engine, Donald E. Hagen, Prem Lobo, Philip D. Whitefield, Max B. Trueblood
Physics Faculty Research & Creative Works
During Project AAFEX, PM emissions measurements were conducted on a CFM56-2C1 gas turbine engine in January 2009 in Palmdale CA. The engine was mounted on a NASA DC-8 aircraft, which was parked on the runway, and emission samples were extracted at the engine exit plane (1m), in the near field (30m), and in the advected plume (145m). The engine was operated at several power levels, and burned several fuels: JP-8, a Fischer-Tropsch fuel derived from natural gas (FT1), and a second Fischer-Tropsch fuel derived from gasified coal (FT2). In addition to these fuels, 50:50 blends of the Fischer-Tropsch fuels and …
Doping Dependence Of Spin-Lattice Coupling And Two-Dimensional Ordering In Multiferroic Hexagonal Y₁₋ₓluₓmno₃ (0 ≤ X ≤ 1), Junghwan Park, Seongsu Lee, Misun Kang, Kwanghyun Jang, Changhee Lee, Sergey V. Streltsov, Vladimir V. Mazurenko, Maria V. Valentyuk, Julia E. Medvedeva, Takashi Kamiyama, Jegeun Park
Doping Dependence Of Spin-Lattice Coupling And Two-Dimensional Ordering In Multiferroic Hexagonal Y₁₋ₓluₓmno₃ (0 ≤ X ≤ 1), Junghwan Park, Seongsu Lee, Misun Kang, Kwanghyun Jang, Changhee Lee, Sergey V. Streltsov, Vladimir V. Mazurenko, Maria V. Valentyuk, Julia E. Medvedeva, Takashi Kamiyama, Jegeun Park
Physics Faculty Research & Creative Works
We have examined a complete phase diagram of Y1-x Lu xMnO3 with 0≤x≤1 by using bulk measurements and neutron-diffraction studies. With increasing Lu concentration, Curie-Weiss temperature and Neel temperature are found to increase continuously while the two-dimensional nature of short-range magnetic correlation persists even in the paramagnetic phase throughout the entire doping range. At the same time, the lattice constants and the unit-cell volume get contracted with Lu doping, i.e., chemical pressure effect. This decrease in the lattice constants and the unit-cell volume then leads naturally to an increased magnetic exchange interaction as found in our local …
Anomalously Elastic Intermediate Phase In Randomly Layered Superfluids, Superconductors, And Planar Magnets, Priyanka Mohan, Paul M. Goldbart, Rajesh Narayanan, John Toner, Thomas Vojta
Anomalously Elastic Intermediate Phase In Randomly Layered Superfluids, Superconductors, And Planar Magnets, Priyanka Mohan, Paul M. Goldbart, Rajesh Narayanan, John Toner, Thomas Vojta
Physics Faculty Research & Creative Works
We show that layered quenched randomness in planar magnets leads to an unusual intermediate phase between the conventional ferromagnetic low-temperature and paramagnetic high-temperature phases. In this intermediate phase, which is part of the Griffiths region, the spin-wave stiffness perpendicular to the random layers displays anomalous scaling behavior, with a continuously variable anomalous exponent, while the magnetization and the stiffness parallel to the layers both remain finite. Analogous results hold for superfluids and superconductors. We study the two phase transitions into the anomalous elastic phase, and we discuss the universality of these results, and implications of finite sample size as well …
Theoretical Fully Differential Cross Sections For Double-Charge-Transfer Collisions, Allison L. Harris, Jerry Peacher, Don H. Madison
Theoretical Fully Differential Cross Sections For Double-Charge-Transfer Collisions, Allison L. Harris, Jerry Peacher, Don H. Madison
Physics Faculty Research & Creative Works
We present a four-body model for double charge transfer, called the four-body double-capture model. This model explicitly treats all four particles in the collision, and we apply it here to fully differential cross sections (FDCSs) for proton+helium collisions. The effects of initial- and final-state electron correlations are studied, as well as the role of the projectile-nucleus interaction. We also present results for proton+helium single capture, as well as single-capture:double-capture ratios of FDCSs.
Polarization And Ellipticity Of High-Order Harmonics From Aligned Molecules Generated By Linearly Polarized Intense Laser Pulses, Anh-Thu Le, R. R. Lucchese, C. D. Lin
Polarization And Ellipticity Of High-Order Harmonics From Aligned Molecules Generated By Linearly Polarized Intense Laser Pulses, Anh-Thu Le, R. R. Lucchese, C. D. Lin
Physics Faculty Research & Creative Works
We present theoretical calculations for polarization and ellipticity of high-order harmonics from aligned N₂, CO₂, and O₂ molecules generated by linearly polarized lasers. Within the rescattering model, the two polarization amplitudes of the harmonics are determined by the photo-recombination amplitudes for photons emitted with polarization parallel or perpendicular to the direction of the same returning electron wave packet. Our results show clear species-dependent polarization states, in excellent agreement with experiments. We further note that the measured polarization ellipse of the harmonic furnishes the needed parameters for a "complete" experiment in molecules.
Scaled Vapor-To-Liquid Nucleation In A Lennard-Jones System, Barbara N. Hale, Mark Thomason
Scaled Vapor-To-Liquid Nucleation In A Lennard-Jones System, Barbara N. Hale, Mark Thomason
Physics Faculty Research & Creative Works
Scaling of the homogenous vapor-to-liquid nucleation rate, J, is observed in a model Lennard-Jones (LJ) system. The model uses Monte Carlo simulation-generated small cluster growth to decay rate constant ratios and the kinetic steady-state nucleation rate formalism to determine J at four temperatures below the LJ critical temperature, Tc. When plotted vs the scaled supersaturation, lnS/[Tc/T-1]3/2, the values of log J are found to collapse onto a single line. A similar scaling has been observed for the experimental nucleation rate data of water and toluene.
Anderson Localization As Position-Dependent Diffusion In Disordered Waveguides, Ben Payne, Alexey Yamilov, Sergey E. Skipetrov
Anderson Localization As Position-Dependent Diffusion In Disordered Waveguides, Ben Payne, Alexey Yamilov, Sergey E. Skipetrov
Physics Faculty Research & Creative Works
We show that the recently developed self-consistent theory of Anderson localization with a position-dependent diffusion coefficient is in quantitative agreement with the supersymmetry approach up to terms of the order of 1/g 02 (with g0 the dimensionless conductance in the absence of interference effects) and with large-scale ab initio simulations of the classical wave transport in disordered waveguides, at least for g 0 ~ 0.5. In the latter case, agreement is found even in the presence of absorption. Our numerical results confirm that in open disordered media, the onset of Anderson localization can be viewed as position-dependent diffusion.
Differential Cross Sections For Non-Sequential Double Ionization Of He By 52 Ev Photons From The Free Electron Laser In Hamburg, Flash, Moritz Kurka, Johannes Feist, Daniel A. Horner, Artem Rudenko, Yuhai Jiang, Kai Uwe Kuhnel, Lutz M. Foucar, Thomas N. Rescigno, Clyde William Mccurdy, Renate Pazourek, Stefan Nagele, Michael Schulz, Oliver Herrwerth, Matthias Lezius, Matthias F. Kling, Markus S. Schoffler, Ali Belkacem, Stefan Dusterer, Rolf Treusch, Barry I. Schneider, Lee A. Collins, Joachim Burgdorfer, Claus Dieter Schroter
Differential Cross Sections For Non-Sequential Double Ionization Of He By 52 Ev Photons From The Free Electron Laser In Hamburg, Flash, Moritz Kurka, Johannes Feist, Daniel A. Horner, Artem Rudenko, Yuhai Jiang, Kai Uwe Kuhnel, Lutz M. Foucar, Thomas N. Rescigno, Clyde William Mccurdy, Renate Pazourek, Stefan Nagele, Michael Schulz, Oliver Herrwerth, Matthias Lezius, Matthias F. Kling, Markus S. Schoffler, Ali Belkacem, Stefan Dusterer, Rolf Treusch, Barry I. Schneider, Lee A. Collins, Joachim Burgdorfer, Claus Dieter Schroter
Physics Faculty Research & Creative Works
Two-photon double ionization of He is studied at the Free Electron Laser in Hamburg (FLASH) by inspecting He2+ momentum (P-(He 2+)) distributions at 52 eV photon energy. We demonstrate that recoil ion momentum distributions can be used to infer information about highly correlated electron dynamics and find the first experimental evidence for 'virtual sequential ionization'. The experimental data are compared with the results of two calculations, both solving the time-dependent Schrodinger equation. We find good overall agreement between experiment and theory, with significant differences for cuts along the polarization direction that cannot be explained by the experimental resolution …
Astronomy's New Messengers: A Traveling Exhibit To Reach Out To A Young Adult Audience, Marco Cavaglia, Martin Hendry, Szabolocs Marka, David H. Reitze, Keith Riles
Astronomy's New Messengers: A Traveling Exhibit To Reach Out To A Young Adult Audience, Marco Cavaglia, Martin Hendry, Szabolocs Marka, David H. Reitze, Keith Riles
Physics Faculty Research & Creative Works
The Laser Interferometer Gravitational-wave Observatory exhibit Astronomy's New Messengers: Listening to the Universe with Gravitational Waves is traveling to colleges, universities, museums and other public institutions throughout the United States. In 2010, an extended version of this exhibit will appear in a New York City venue that is accessible to a large and diverse cross section of the general public. Astronomy's New Messengers primarily communicates with an adolescent and young adult audience, potentially inspiring them into the field of science. Acknowledging that this audience is traditionally a difficult one to attract, the exhibit publicly announces itself in a charismatic fashion …
Order-Dependent Mappings: Strong-Coupling Behavior From Weak-Coupling Expansions In Non-Hermitian Theories, Jean Zinn-Justin, Ulrich D. Jentschura
Order-Dependent Mappings: Strong-Coupling Behavior From Weak-Coupling Expansions In Non-Hermitian Theories, Jean Zinn-Justin, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
A long time ago, it has been conjectured that a Hamiltonian with a potential of the form x 2+ivx 3, v real, has a real spectrum. This conjecture has been generalized to a class of the so-called PT symmetric Hamiltonians and some proofs have been given. Here, we show by numerical investigation that the divergent perturbation series can be summed efficiently by an order-dependent mapping (ODM) in the whole complex plane of the coupling parameter v 2, and that some information about the location of level-crossing singularities can be obtained in this way. Furthermore, we discuss to …
Fivefold Differential Cross Sections For Ground-State Ionization Of Aligned H₂ By Electron Impact, Arne Senftleben, Ola A. Al-Hagan, Thomas Pfluger, Xueguang Ren, Don H. Madison, Alexander Dorn, Joachim Hermann Ullrich
Fivefold Differential Cross Sections For Ground-State Ionization Of Aligned H₂ By Electron Impact, Arne Senftleben, Ola A. Al-Hagan, Thomas Pfluger, Xueguang Ren, Don H. Madison, Alexander Dorn, Joachim Hermann Ullrich
Physics Faculty Research & Creative Works
We discuss the ionization of aligned hydrogen molecules into their ionic ground state by 200 eV electrons. Using a reaction microscope, the complete electron scattering kinematics is imaged over a large solid angle. Simultaneously, the molecular alignment is derived from postcollision dissociation of the residual ion. It is found that the ionization cross section is maximized for small angles between the internuclear axis and the momentum transfer. Fivefold differential cross sections (5DCSs) reveal subtle differences in the scattering process for the distinct alignments. We compare our observations with theoretical 5DCSs obtained with an adapted molecular three-body distorted wave model that …
First Mediterranean Conference On Classical And Quantum Gravity (Mccqg 2009): Preface, Spyros Basilakos, Mariano Cadoni, Marco Cavaglia, Theodosios Christodoulakis, Elias C. Vagenas
First Mediterranean Conference On Classical And Quantum Gravity (Mccqg 2009): Preface, Spyros Basilakos, Mariano Cadoni, Marco Cavaglia, Theodosios Christodoulakis, Elias C. Vagenas
Physics Faculty Research & Creative Works
No abstract provided.
Miniaturized Superconducting Metamaterials For Radio Frequencies, Cihan Kurter, John A. Abrahams, Steven Mark Anlage
Miniaturized Superconducting Metamaterials For Radio Frequencies, Cihan Kurter, John A. Abrahams, Steven Mark Anlage
Physics Faculty Research & Creative Works
We have developed a low-loss, ultrasmall radio frequency (rf) metamaterial operating at ~76 MHz. This miniaturized medium is made up of planar spiral elements with diameter as small as ~λ/658 (λ is the free space wavelength), fashioned from Nb thin films on quartz substrates. The transmission data are examined below and above the superconducting transition temperature of Nb for both a single spiral and a one dimensional array. The validity of the design is tested through numerical simulations and good agreement is found. We discuss how superconductors enable such a compact design in the rf with high loaded-quality factor (in …
Counterintuitive Consequence Of Heating In Strongly-Driven Intrinsic Junctions Of Bi₂Sr₂Cacu₂O8+Δ Mesas, Cihan Kurter, Lutfi Ozyuzer, Thomas Proslier, John F. Zasadzinski, David G. Hinks, Kenneth E. Gray
Counterintuitive Consequence Of Heating In Strongly-Driven Intrinsic Junctions Of Bi₂Sr₂Cacu₂O8+Δ Mesas, Cihan Kurter, Lutfi Ozyuzer, Thomas Proslier, John F. Zasadzinski, David G. Hinks, Kenneth E. Gray
Physics Faculty Research & Creative Works
Anomalously high and sharp peaks in the conductance of intrinsic Josephson junctions in Bi2 Sr2 CaCu2 O 8+δ (Bi2212) mesas have been commonly interpreted as superconducting energy gaps but here we show they are a result of strong self-heating. This conclusion follows directly from a comparison to the equilibrium gap measured by tunneling in single break junctions on equivalent crystals. As the number of junctions in the mesa, N, and thus heating increase, the peak voltages decrease and the peak width abruptly sharpens for N≥12. Clearly these widely variable features vs N cannot all represent the equilibrium …