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13 results on '"Institut für Physik [Mainz]"'

1. Summertime observations of elevated levels of ultrafine particles in the high Arctic marine boundary layer

Author

Johannes Schneider, Heiko Bozem, Peter Hoor, Kathy S. Law, W. Richard Leaitch, Megan D. Willis, Andreas Herber, Julia Burkart, Jennie L. Thomas, Jonathan P. D. Abbatt, Amir A. Aliabadi, Franziska Köllner, Department of Chemistry [University of Toronto], University of Toronto, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Environmental Engineering Program [Guelph], University of Guelph, Max Planck Institute for Chemistry (MPIC), Max-Planck-Gesellschaft, Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Environment and Climate Change Canada, European Union, European Project: 265863,EC:FP7:TPT,FP7-OCEAN-2010,ACCESS(2011), and Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU)

Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Atmospheric Science, 010504 meteorology & atmospheric sciences, 010501 environmental sciences, Atmospheric sciences, 01 natural sciences, lcsh:QC1-999, Aerosol, lcsh:Chemistry, Troposphere, Fog, Boundary layer, lcsh:QD1-999, Arctic, Fast ice, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, 13. Climate action, Climatology, Ultrafine particle, Environmental science, Cloud condensation nuclei, 14. Life underwater, lcsh:Physics, 0105 earth and related environmental sciences
Abstract

Motivated by increasing levels of open ocean in the Arctic summer and the lack of prior altitude-resolved studies, extensive aerosol measurements were made during 11 flights of the NETCARE July 2014 airborne campaign from Resolute Bay, Nunavut. Flights included vertical profiles (60 to 3000 m above ground level) over open ocean, fast ice, and boundary layer clouds and fogs. A general conclusion, from observations of particle numbers between 5 and 20 nm in diameter (N5 − 20), is that ultrafine particle formation occurs readily in the Canadian high Arctic marine boundary layer, especially just above ocean and clouds, reaching values of a few thousand particles cm−3. By contrast, ultrafine particle concentrations are much lower in the free troposphere. Elevated levels of larger particles (for example, from 20 to 40 nm in size, N20 − 40) are sometimes associated with high N5 − 20, especially over low clouds, suggestive of aerosol growth. The number densities of particles greater than 40 nm in diameter (N > 40) are relatively depleted at the lowest altitudes, indicative of depositional processes that will lower the condensation sink and promote new particle formation. The number of cloud condensation nuclei (CCN; measured at 0.6 % supersaturation) are positively correlated with the numbers of small particles (down to roughly 30 nm), indicating that some fraction of these newly formed particles are capable of being involved in cloud activation. Given that the summertime marine Arctic is a biologically active region, it is important to better establish the links between emissions from the ocean and the formation and growth of ultrafine particles within this rapidly changing environment.

Published
2017
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2. Design for a high resolution electron energy loss microscope

Author

A. Lafosse, Marian Mankos, Gerd Schönhense, L. Amiaud, Daniel Comparat, Nicholas Barrett, Khashayar Shadman, Raphaël Hahn, Yan J. Picard, O. Fedchenko, Electron Optica Inc., Laboratoire Aimé Cotton (LAC), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Institut des Sciences Moléculaires d'Orsay (ISMO), Laboratoire d'Etude des NanoStructures et Imagerie de Surface (LENSIS), Service de physique de l'état condensé (SPEC - UMR3680), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut Rayonnement Matière de Saclay (IRAMIS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, and Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU)

Subjects
Microscope, Materials science, EELS, Phonon, 02 engineering and technology, Electron, 01 natural sciences, law.invention, Optics, law, surface imaging, 0103 physical sciences, Microscopy, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Instrumentation, Image resolution, LEEM, 010302 applied physics, Spectrometer, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], business.industry, 021001 nanoscience & nanotechnology, Laser, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Excited state, 0210 nano-technology, business
Abstract

International audience; An electron optical column has been designed for High Resolution Electron Energy Loss Microscopy (HREELM). The column is composed of electron lenses and a beam separator that are placed between an electron source based on a laser excited cesium atom beam and a time-of-flight (ToF) spectrometer or a hemispherical analyzer (HSA). The instrument will be able to perform full field low energy electron imaging of surfaces with sub-micron spatial resolution and meV energy resolution necessary for the analysis of local vibrational spectra. Thus, noncontact, real space mapping of microscopic variations in vibrational levels will be made possible. A second imaging mode will allow for the mapping of the phonon dispersion relations from microscopic regions defined by an appropriate field aperture.

Published
2019
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3. Slodowy slices and universal Poisson deformations

Author

Manfred Lehn, Yoshinori Namikawa, Christoph Sorger, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Department of Mathematics, Kyoto University [Kyoto], Laboratoire de Mathématiques Jean Leray (LMJL), Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN), and ANR-09-BLAN-0104,VHSMOD-2009,Variétés holomorphiquement symplectiques, leurs espaces de modules et formes automorphes(2009)

Subjects
Pure mathematics, Algebra and Number Theory, 010102 general mathematics, Dimension (graph theory), Poisson distribution, 01 natural sciences, 14B07, 17B45, 17B63, Mathematics - Algebraic Geometry, symbols.namesake, Nilpotent, Mathematics::Algebraic Geometry, Simple (abstract algebra), 0103 physical sciences, Lie algebra, FOS: Mathematics, symbols, [MATH.MATH-AG]Mathematics [math]/Algebraic Geometry [math.AG], 010307 mathematical physics, 0101 mathematics, Mathematics::Representation Theory, Algebraic Geometry (math.AG), Symplectic geometry, Mathematics
Abstract

We classify the nilpotent orbits in a simple Lie algebra for which the restriction of the adjoint quotient map to a Slodowy slice is the universal Poisson deformation of its central fibre. This generalises work of Brieskorn and Slodowy on subregular orbits. In particular, we find in this way new singular symplectic hypersurfaces of dimension 4 and 6., Comment: 29 p. Minor changes. Final version. To appear in Compositio Mathematica

Published
2011
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4. Euclidean random matrix theory: low-frequency non-analyticities and Rayleigh scattering

Author

Walter Schirmacher, Carl Ganter, Institut für Radiologie, Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), Institut für Physik [Mainz], and Johannes Gutenberg - Universität Mainz (JGU)

Subjects
Physics, Density matrix, Statistical Mechanics (cond-mat.stat-mech), Autocorrelation, FOS: Physical sciences, Inverse, Disordered Systems and Neural Networks (cond-mat.dis-nn), Condensed Matter - Disordered Systems and Neural Networks, 16. Peace & justice, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, symbols.namesake, Self-energy, TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY, Quantum mechanics, Physical Sciences, 0103 physical sciences, Euclidean geometry, symbols, Rayleigh scattering, Diffusion (business), 010306 general physics, Random matrix, Condensed Matter - Statistical Mechanics
Abstract

By calculating all terms of the high-density expansion of the euclidean random matrix theory (up to second-order in the inverse density) for the vibrational spectrum of a topologically disordered system we show that the low-frequency behavior of the self energy is given by $\Sigma(k,z)\propto k^2z^{d/2}$ and not $\Sigma(k,z)\propto k^2z^{(d-2)/2}$, as claimed previously. This implies the presence of Rayleigh scattering and long-time tails of the velocity autocorrelation function of the analogous diffusion problem of the form $Z(t)\propto t^{(d+2)/2}$., Comment: 27 pages

Published
2011
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5. Many-body physics with ultracold gases

Author

Jean Dalibard, Wilhelm Zwerger, Immanuel Bloch, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), Laboratoire Kastler Brossel (LKB (Lhomond)), Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institute for Theoretical Physics, TUM (ITP-TUM), Technische Universitaet Muenchen, Dalibard, Jean, Johannes Gutenberg - Universität Mainz (JGU), Université Pierre et Marie Curie - Paris 6 (UPMC)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Condensed Matter::Quantum Gases, Physics, Hubbard model, Condensed Matter::Other, FOS: Physical sciences, General Physics and Astronomy, BCS theory, Bose–Hubbard model, 01 natural sciences, 010305 fluids & plasmas, law.invention, Condensed Matter - Other Condensed Matter, Coupling (physics), Tonks–Girardeau gas, [PHYS.COND.CM-GEN] Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], law, Ultracold atom, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], Quantum mechanics, Quantum electrodynamics, 0103 physical sciences, Atomtronics, 010306 general physics, Bose–Einstein condensate, Other Condensed Matter (cond-mat.other)
Abstract

This article reviews recent experimental and theoretical progress on many-body phenomena in dilute, ultracold gases. Its focus are effects beyond standard weak-coupling descriptions, like the Mott-Hubbard-transition in optical lattices, strongly interacting gases in one and two dimensions or lowest Landau level physics in quasi two-dimensional gases in fast rotation. Strong correlations in fermionic gases are discussed in optical lattices or near Feshbach resonances in the BCS-BEC crossover., revised version, accepted for publication in Rev. Mod. Phys

Published
2008
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6. Recent developments in the manipulation of magnetic domain walls in CoFeB–MgO wires for applications to high-density nonvolatile memories

Author

Pham , Van Tuong, Marty , Williams, Marty , Matthieu, Marty , Jean-Philippe, Zahnd , Gilles, Pham , T., Marty , Alain, Laczkowski , L, Savero Torres , T, Beigne , C., Vergnaud , C., Jamet , M., Attané , A, Ravelosona , D., Diez , L. Herrera, Zhao , W., Kläui , M., Ockert , B., Mantovan , R., Lamperti , A., Baldi , L., Jacques , V., Vila , Laurent, Cowburn , R., SPINtronique et TEchnologie des Composants ( SPINTEC ), Institut Nanosciences et Cryogénie ( INAC ), Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Grenoble Alpes ( UGA ) -Commissariat à l'énergie atomique et aux énergies alternatives ( CEA ) -Université Grenoble Alpes ( UGA ) -Centre National de la Recherche Scientifique ( CNRS ), SC2G - Semi-conducteurs à large bande interdite, Institut Néel ( NEEL ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ), Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés ( LISBP ), Institut National de la Recherche Agronomique ( INRA ) -Institut National des Sciences Appliquées - Toulouse ( INSA Toulouse ), Institut National des Sciences Appliquées ( INSA ) -Institut National des Sciences Appliquées ( INSA ) -Centre National de la Recherche Scientifique ( CNRS ), Institut d'électronique fondamentale ( IEF ), Université Paris-Sud - Paris 11 ( UP11 ) -Centre National de la Recherche Scientifique ( CNRS ), Systèmes interfaciaux à l'echelle nanometrique ( SIEN ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -ESPCI ParisTech-Centre National de la Recherche Scientifique ( CNRS ), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz ( JGU ), Laboratoire de Physique des Solides ( LPS ), Institut d'électronique fondamentale (IEF), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Johannes Gutenberg - Universität Mainz (JGU), Singulus technology AG, Laboratorio MDM (IMM-CNR), Consiglio Nazionale delle Ricerche [Roma] (CNR), Laboratoire de Physique des Solides (LPS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), SPINtronique et TEchnologie des Composants (SPINTEC), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), University of Cambridge [UK] (CAM), Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)

Subjects
Materials science, Spintronics, Magnetic domain, Condensed matter physics, business.industry, [ PHYS.COND.CM-MS ] Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 02 engineering and technology, magnetic domain walls, magnetic anisotropy, mass storage, 021001 nanoscience & nanotechnology, 01 natural sciences, Engineering physics, Magnetic field, Domain wall (magnetism), Semiconductor, CMOS, Electric field, 0103 physical sciences, Computer data storage, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, business, ComputingMilieux_MISCELLANEOUS, [ PHYS.COND ] Physics [physics]/Condensed Matter [cond-mat]
Abstract

The recent discovery that magnetic domain walls can be moved under a small current without any magnetic field opens a perspective for a paradigm shift in mass storage design. However, several fundamental questions must be answered before the technology can be considered feasible. This review covers the current understanding of domain wall (DW) propagation in CoFeB–MgO structures with perpendicular magnetic anisotropy. These films exhibit a very low density of pinning centers and can be integrated in Magnetic Tunnel Junctions, making them very promising for manipulating multiple domain walls in ultra-high-density spintronic devices. Several important issues are addressed: the physics of magnetic field, current and electric field driven domain wall motion, the characterization of the pinning potential on the nanoscale, the demonstration of artificial storing pinning sites, and the evaluation of domain wall propagation for logic and memory design integrated into complementary metal-oxide semiconductor (CMOS) technology.

Published
2015
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7. Scaling behaviour of lattice animals at the upper critical dimension

Author

Damien P. Foster, Christian von Ferber, Ralph Kenna, Hsiao-Ping Hsu, Dpt of Applied Maths Coventry (DAM Coventry), Coventry University, Laboratoire de Physique Théorique et Modélisation (LPTM - UMR 8089), Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), and Foster, Damien

Subjects
Logarithm, Statistical Mechanics (cond-mat.stat-mech), Linear polymer, FOS: Physical sciences, Condensed Matter Physics, 01 natural sciences, Gyration, 010305 fluids & plasmas, Electronic, Optical and Magnetic Materials, [PHYS.COND.CM-SM] Physics [physics]/Condensed Matter [cond-mat]/Statistical Mechanics [cond-mat.stat-mech], Lattice (order), 0103 physical sciences, Order (group theory), Partition (number theory), Statistical physics, [PHYS.COND.CM-SM]Physics [physics]/Condensed Matter [cond-mat]/Statistical Mechanics [cond-mat.stat-mech], 010306 general physics, Scaling, Critical dimension, Condensed Matter - Statistical Mechanics, Mathematics
Abstract

We perform numerical simulations of the lattice-animal problem at the upper critical dimension d=8 on hypercubic lattices in order to investigate logarithmic corrections to scaling there. Our stochastic sampling method is based on the pruned-enriched Rosenbluth method (PERM), appropriate to linear polymers, and yields high statistics with animals comprised of up to 8000 sites. We estimate both the partition sums (number of different animals) and the radii of gyration. We re-verify the Parisi-Sourlas prediction for the leading exponents and compare the logarithmic-correction exponents to two partially differing sets of predictions from the literature. Finally, we propose, and test, a new Parisi-Sourlas-type scaling relation appropriate for the logarithmic-correction exponents., Comment: 10 pages, 5 figures

Published
2011
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8. Spectroscopy of the electronic states of the Heusler compounds Co2FeAl and Co2Cr0.6Fe0.4Al and the influence of oxidation

Author

Fabian Große-Schulte, Martin Jourdan, Gerd Schönhense, Michaela Hahn, Institut für Physik [Mainz], and Johannes Gutenberg - Universität Mainz (JGU)

Subjects
Materials science, Acoustics and Ultrasonics, Photoemission spectroscopy, Inverse photoemission spectroscopy, Analytical chemistry, Angle-resolved photoemission spectroscopy, Fermi energy, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, 13. Climate action, Chemisorption, Excited state, Physical Sciences, 0103 physical sciences, 010306 general physics, 0210 nano-technology, Electronic band structure, Spectroscopy
Abstract

The band structures of the Heusler compounds Co2Cr0.6Fe0.4Al and Co2FeAl were investigated in situ by angle-resolved ultraviolet photoemission spectroscopy. The samples were prepared by a sputtering process optimized for tunnelling junction preparation, the photoemission process in the normal direction of the (0 0 1)-oriented thin films was excited by a helium gas discharge lamp (hν = 21.2 eV and hν = 40.8 eV). The spectra of clean samples are compared with calculations of the total and partial bulk density of states and are evaluated within the three-step model of photoemission. Basic agreement with theoretical predictions of the bulk band structure is concluded. At oxygen exposures of the thin films of only 1 Langmuir a chemisorption phase with significant changes in the valence-band spectrum near the Fermi energy is observed. At 10 L oxygen the spectra are indicative of an oxide within the UPS probing depth.

Published
2011
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9. Structure of191Pb from α- and β-decay spectroscopy

Author

S.G. Zemlyanoy, Yu. Kudryavtsev, D. V. Fedorov, Andrei Andreyev, P. L. Molkanov, G. Huber, A. E. Barzakh, J. Büscher, Mark Huyse, B. A. Marsh, M. D. Seliverstov, M. Keupers, Iain Darby, Thomas Elias Cocolios, V. N. Fedosseev, B. Bastin, S. Antalic, S. Franchoo, E Mané, I. Stefan, J. Van de Walle, M. Venhart, W. Dexters, Kieran Flanagan, P. Van Duppen, R. D. Page, A. M. Sjoedin, Ulli Köster, Instituut voor Kern- en Stralingsfysica, Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), School of Engineering and Science, University of the West of Scotland (UWS), Department of Physics and Biophysics, Comenius University in Bratislava, Petersburg Nuclear Physics Institute, Engineering Department, CERN [Genève], Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, Department of Physics, University of Manchester [Manchester], Institut de Physique Nucléaire d'Orsay, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Institut Laue-Langevin (ILL), ILL, Oliver Lodge Laboratory, University of Liverpool, Royal Institute of Technology [Stockholm] (KTH ), ISOLDE, Institute of Physics, Slovak Academy of Science [Bratislava] (SAS), Flerov Laboratory of Nuclear Reactions [Dubna] (FLNR), Joint Institute for Nuclear Research (JINR), and KVI - Center for Advanced Radiation Technology

Subjects
Physics, Nuclear and High Energy Physics, Large Hadron Collider, 010308 nuclear & particles physics, Branching fraction, Alpha particle, 01 natural sciences, Beta decay, Nuclear physics, Physical Sciences, 0103 physical sciences, Physics::Accelerator Physics, High Energy Physics::Experiment, Alpha decay, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy
Abstract

International audience; Complementary studies of 191 Pb have been made in the β decay of 191 Bi at LISOL (CRC) and in the α decay of 195 Po at ISOLDE (CERN). Fine structures in the α decay of the low-spin and high-spin isomers of 195 Po have been fully resolved. Identification of the parent state is made possible via isomer selection based on narrowband laser frequency scanning. The α-particle and γ-ray energies have been determined with greater precision. New α-particle and γ-ray energies are identified. Branching ratios in the decay of 195 Po and 191 Pb have been examined. Structure of 191 Pb from α- and β-decay spectroscopy 2 PACS numbers: 23.20.Nx Internal conversion, 23.60.+e α decay, 27.80.+w 190 ≤ A ≤ 219, 29.38.-c Radioactive beams, 32.10.Fn Fine and hyperfine structure Structure of 191 Pb from α- and β-decay spectroscopy 3

Published
2010
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10. Isotope shift measurements in the 2s1/2→ 2p3/2transition of Be+and extraction of the nuclear charge radii for7, 10, 11Be

Author

Mark Bissell, M. Žáková, Ch Geppert, Magda Kowalska, J. Krämer, Claus Zimmermann, A. Krieger, Klaus Blaum, Ferdinand Schmidt-Kaler, Z Andjelkovic, Deyan T. Yordanov, Matthias Lochmann, Gordon W. F. Drake, Rodolfo Sánchez, Wilfried Nörtershäuser, Rainer Neugart, D. Tiedemann, Zong-Chao Yan, T. Neff, Institut für Kernchemie, Universität Mainz, Instituut voor Kern- en Stralingsfysica, Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Max-Planck-Institut für Kernphysik (MPIK), Max-Planck-Gesellschaft, Department of Physics, University of Windsor [Ca], Helmholtz zentrum für Schwerionenforschung GmbH (GSI), Physikalisches Institut [Tübingen], Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen, Physics Department, CERN [Genève], Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Universität Ulm - Ulm University [Ulm, Allemagne], Physics Department [UNB], and University of New Brunswick (UNB)

Subjects
Physics, Nuclear and High Energy Physics, Isotope, 010308 nuclear & particles physics, Halo nucleus, 01 natural sciences, 7. Clean energy, Effective nuclear charge, Ion, Charge radius, Physical Sciences, 0103 physical sciences, Neutron, Halo, Atomic physics, Nuclear Experiment, 010306 general physics, Spectroscopy
Abstract

International audience; shift measurements in the 2s 1/2 → 2p 3/2 transition of Be + and extraction of the nuclear charge radii for 7, 10, 11 Be Abstract. We have performed isotope shift measurements in the 2s 1/2 → 2p 3/2 transition of Be + ions using advanced collinear laser spectroscopy with two counterpropagating laser beams. Measurements involving a frequency comb for laser stabilization and absolute frequency determination allowed us to determine the isotope shifts with an accuracy of 2 MHz. From the isotope shifts between 9 Be and 7, 10, 11 Be, high-accuracy mass shift calculations and the charge radius of the reference isotope 9 Be we determined nuclear charge radii for the isotopes 7, 10 Be and the one-neutron halo nucleus 11 Be. The results are compared to nuclear-structure calculations using the Fermionic Molecular Dynamics model which reproduce well the general trend of the radii. Decreasing charge radii from 7 Be to 10 Be are explained by the cluster structure of the nuclei. The increase from 10 Be to 11 Be is mainly caused by the halo neutron by which the 10 Be core moves relative to the center of mass. Polarization of the 10 Be core has only a small influence on the charge radius.

Published
2010
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11. Quantitative determination of domain wall coupling energetics

Author

Markus Laufenberg, Frithjof Nolting, Mathias Kläui, C. A. F. Vaz, Dirk Backes, Stefan Heun, J. A. C. Bland, Andrea Locatelli, T. Kasama, Ulrich Rüdiger, H. Ehrke, Salia Cherifi, Rafal E. Dunin-Borkowski, Daniel Bedau, Laura J. Heyderman, Fachbereich Physik [Konstanz], University of Konstanz, Department of Physics [New York], New York University [New York] (NYU), NYU System (NYU)-NYU System (NYU), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Paul Scherrer Institute (PSI), Cavendish Laboratory, University of Cambridge [UK] (CAM), Laboratoire Louis Néel (LLN), Centre National de la Recherche Scientifique (CNRS), and Elettra Sincrotrone Trieste

Subjects
electron holography, Materials science, Physics and Astronomy (miscellaneous), magnetic structure, 02 engineering and technology, 01 natural sciences, Electron holography, Condensed Matter::Materials Science, 75.60.Ch, 75.50.Cc, 75.50.Bb, 75.25.+z, 75.50.Tt, 78.20.Ls, 0103 physical sciences, nanostructured materials, ddc:530, 010306 general physics, Condensed matter physics, Magnetic circular dichroism, Demagnetizing field, 021001 nanoscience & nanotechnology, Vortex, Photoemission electron microscopy, photoelectron microscopy, Domain wall (magnetism), Ferromagnetism, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], magnetic domain walls, 0210 nano-technology, Magnetic dipole–dipole interaction, magnetic circular dichroism
Abstract

International audience; The magnetic dipolar coupling of head-to-head domain walls is studied in 350 nm wide NiFe and Co nanostructures by high resolution magnetic imaging. We map the stray field of a domain wall directly with sub-10-nm resolution using off-axis electron holography and find that the field intensity decreases as 1/r with distance. By using x-ray magnetic circular dichroism photoemission electron microscopy, we observe that the spin structures of interacting domain walls change from vortex to transverse walls, when the distance between the walls is reduced to below (77±5) nm for 27 nm thick NiFe and (224±65) nm for 30 nm thick Co elements. Using measured stray field values, the energy barrier height distribution for the nucleation of a vortex core is obtained.

Published
2006
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12. Tonks-Girardeau Gas of Ultracold Atoms in an Optical Lattice

Author

Valentin Murg, Artur Widera, G. V. Shlyapnikov, Simon Fölling, Olaf Mandel, Immanuel Bloch, Ignacio Cirac, B. Paredes, Theodor W. Hänsch, Max-Planck-Institut für Quantenoptik (MPQ), Max-Planck-Gesellschaft, Sektion Physik (SEKTION PHYSIK), Ludwig-Maximilians-Universität München (LMU), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Sektion Physik, Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Van der Waals-Zeeman Institute, University of Amsterdam [Amsterdam] (UvA), Quantum Gases & Quantum Information (WZI, IoP, FNWI), and Le Vaou, Claudine

Subjects
Physics, Condensed Matter::Quantum Gases, Optical lattice, Multidisciplinary, Condensed matter physics, Fermion, 01 natural sciences, 010305 fluids & plasmas, Fermionic condensate, Tonks–Girardeau gas, symbols.namesake, Pauli exclusion principle, Effective mass (solid-state physics), Ultracold atom, Quantum mechanics, 0103 physical sciences, symbols, 010306 general physics, Boson
Abstract

Strongly correlated quantum systems are among the most intriguing and fundamental systems in physics. One such example is the Tonks−Girardeau gas1, 2, proposed about 40 years ago, but until now lacking experimental realization; in such a gas, the repulsive interactions between bosonic particles confined to one dimension dominate the physics of the system. In order to minimize their mutual repulsion, the bosons are prevented from occupying the same position in space. This mimics the Pauli exclusion principle for fermions, causing the bosonic particles to exhibit fermionic properties1, 2. However, such bosons do not exhibit completely ideal fermionic (or bosonic) quantum behaviour; for example, this is reflected in their characteristic momentum distribution3. Here we report the preparation of a Tonks−Girardeau gas of ultracold rubidium atoms held in a two-dimensional optical lattice formed by two orthogonal standing waves. The addition of a third, shallower lattice potential along the long axis of the quantum gases allows us to enter the Tonks−Girardeau regime by increasing the atoms' effective mass and thereby enhancing the role of interactions. We make a theoretical prediction of the momentum distribution based on an approach in which trapped bosons acquire fermionic properties, finding that it agrees closely with the measured distribution.

Published
2004
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13. Ultrafast Optical Demagnetization manipulates Nanoscale Spin Structure in Domain Walls

Author

Samuel Flewett, K. Li, Christian Gutt, Rolf Treusch, A. Al-Shemmary, Gerhard Grübel, M. Hille, Bastian Pfau, Renaud Delaunay, Nicolas Jaouen, Erik Guehrs, Jyoti Ranjan Mohanty, Stefan Eisebitt, Christian M. Günther, Ranjit R. Hawaldar, Felix Büttner, Jan Geilhufe, Mathias Kläui, Boris Vodungbo, S. Schaffert, Hans Peter Oepen, Stefan Düsterer, Harald Redlin, A. Kobs, William F. Schlotter, Jan Lüning, Robert Frömter, Leonard Müller, Daniel Stickler, Technische Universität Berlin (TU), Deutsches Elektronen-Synchrotron [Hamburg] (DESY), Paul Scherrer Institute (PSI), Ecole Polytechnique Fédérale de Lausanne (EPFL), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Laboratoire de Chimie Physique - Matière et Rayonnement (LCPMR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut für Angewandte Physik [Hamburg] (IAngPh), Universität Hamburg (UHH), Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (Helmholtz-Zentrum Berlin), Helmholtz-Zentrum Berlin, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), SLAC National Accelerator Laboratory (SLAC), Stanford University, Laboratoire d'optique appliquée (LOA), École Nationale Supérieure de Techniques Avancées (ENSTA Paris)-École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Technical University of Berlin / Technische Universität Berlin (TU), Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), and Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
DYNAMICS, Magnetic domain, General Physics and Astronomy, MAGNETIZATION REVERSAL, Physics::Optics, Large scale facilities for research with photons neutrons and ions, Nanotechnology, 02 engineering and technology, Electron, FILMS, 01 natural sciences, Article, General Biochemistry, Genetics and Molecular Biology, Optical pumping, 0103 physical sciences, ddc:530, 010306 general physics, Physics, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Multidisciplinary, Condensed matter physics, Spins, [PHYS.PHYS]Physics [physics]/Physics [physics], Demagnetizing field, ALLOY, General Chemistry, 021001 nanoscience & nanotechnology, Picosecond, Femtosecond, X-RAY, LASER, 0210 nano-technology, Ultrashort pulse
Abstract

During ultrafast demagnetization of a magnetically ordered solid, angular momentum has to be transferred between the spins, electrons, and phonons in the system on femto- and picosecond timescales. Although the intrinsic spin-transfer mechanisms are intensely debated, additional extrinsic mechanisms arising due to nanoscale heterogeneity have only recently entered the discussion. Here we use femtosecond X-ray pulses from a free-electron laser to study thin film samples with magnetic domain patterns. We observe an infrared-pump-induced change of the spin structure within the domain walls on the sub-picosecond timescale. This domain-topography-dependent contribution connects the intrinsic demagnetization process in each domain with spin-transport processes across the domain walls, demonstrating the importance of spin-dependent electron transport between differently magnetized regions as an ultrafast demagnetization channel. This pathway exists independent from structural inhomogeneities such as chemical interfaces, and gives rise to an ultrafast spatially varying response to optical pump pulses., Ultrafast demagnetization occurs when magnetically ordered solids are exposed to femtosecond light pulses, yet the exact spin-transfer mechanism is still debated. Combining ultrashort X-rays and infrared laser pulses, Pfau et al. show the importance of spin transport between domains in thin magnetic films.

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