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

1. Measuring the α-particle charge radius with muonic helium-4 ions

Author: Sandrine Galtier, Julian J. Krauth, Andreas Knecht, Andreas Dax, D. Taqqu, Thomas Graf, Paul Indelicato, Yi-Wei Liu, Karsten Schuhmann, Andreas Voss, F. Mulhauser, Pedro Amaro, Malte Hildebrandt, D. S. Covita, L.M.P. Fernandes, Boris Naar, F. D. Amaro, Theodor W. Hänsch, Marwan Abdou Ahmed, José Paulo Santos, Andrea L. Gouvea, Lucile Julien, Randolf Pohl, Johannes Götzfried, F. Nez, Beatrice Franke, Jorge Machado, Tobias Nebel, C.M.B. Monteiro, J.F.C.A. Veloso, Joaquim M. F. dos Santos, François Biraben, Franz Kottmann, Marc Diepold, Csilla I. Szabo, Jens Hartmann, Jan Vogelsang, Klaus Kirch, Aldo Antognini, Tzu-Ling Chen, Birgit Weichelt, LaserLaB Vrije Universiteit Amsterdam (LaserLaB), Vrije Universiteit Amsterdam [Amsterdam] (VU), Max-Planck-Institute for Quantum Optics, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Institute for Particle Physics and Astrophysics [ETH Zürich] (IPA), Department of Physics [ETH Zürich] (D-PHYS), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Paul Scherrer Institute (PSI), Institut für Strahlwerkzeuge, Universität of Stuttgart, Department of Physics [Coimbra], University of Coimbra [Portugal] (UC), Universidade Nova de Lisboa = NOVA University Lisbon (NOVA), Laboratoire Kastler Brossel (LKB [Collège de France]), 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)-Fédération de recherche du Département de physique de l'Ecole Normale Supérieure - ENS Paris (FRDPENS), 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)-Sorbonne Université (SU)-Collège de France (CdF (institution)), National Tsing Hua University [Hsinchu] (NTHU), Universidade de Aveiro, TRIUMF [Vancouver], Atmosphère, Optique et Spectroscopie (ATMOS), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Ludwig-Maximilians-Universität München (LMU), Theiss Research, Lund University [Lund], Atoms, Molecules, Lasers, LaserLaB - Physics of Light, DF – Departamento de Física, and LIBPhys-UNL
Subjects: Physics, [PHYS]Physics [physics], Multidisciplinary, Muon, Proton, 010308 nuclear & particles physics, Nuclear structure, Atomic spectroscopy, Electron, 01 natural sciences, 7. Clean energy, Article, Ion, [SPI]Engineering Sciences [physics], Charge radius, 0103 physical sciences, [CHIM]Chemical Sciences, Physics::Atomic Physics, Exotic atoms and molecules, Atomic physics, Experimental nuclear physics, 010306 general physics, Spectroscopy, General
Abstract: The energy levels of hydrogen-like atomic systems can be calculated with great precision. Starting from their quantum mechanical solution, they have been refined over the years to include the electron spin, the relativistic and quantum field effects, and tiny energy shifts related to the complex structure of the nucleus. These energy shifts caused by the nuclear structure are vastly magnified in hydrogen-like systems formed by a negative muon and a nucleus, so spectroscopy of these muonic ions can be used to investigate the nuclear structure with high precision. Here we present the measurement of two 2S–2P transitions in the muonic helium-4 ion that yields a precise determination of the root-mean-square charge radius of the α particle of 1.67824(83) femtometres. This determination from atomic spectroscopy is in excellent agreement with the value from electron scattering1, but a factor of 4.8 more precise, providing a benchmark for few-nucleon theories, lattice quantum chromodynamics and electron scattering. This agreement also constrains several beyond-standard-model theories proposed to explain the proton-radius puzzle2,3,4,5, in line with recent determinations of the proton charge radius6,7,8,9, and establishes spectroscopy of light muonic atoms and ions as a precise tool for studies of nuclear properties., Nature, 589 (7843), ISSN:0028-0836, ISSN:1476-4687
Published: 2021
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2. Continuum constitutive laws to describe acoustic attenuation in glasses

Author: Haoming Luo, Anne Tanguy, Valentina M. Giordano, Anthony Gravouil, Walter Schirmacher, Laboratoire de Mécanique des Contacts et des Structures [Villeurbanne] (LaMCoS), Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), (nano)Matériaux pour l'énergie (ENERGIE), Institut Lumière Matière [Villeurbanne] (ILM), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), ONERA, Université Paris Saclay [Palaiseau], ONERA-Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon
Subjects: Physics, [PHYS]Physics [physics], Phonon, Scattering, Attenuation, Glasses, Metamaterial, Mechanics, 01 natural sciences, Viscoelasticity, 010305 fluids & plasmas, Mechanical & acoustical properties, Amorphous materials, [SPI]Engineering Sciences [physics], Macroscopic scale, 0103 physical sciences, Dissipative system, [CHIM]Chemical Sciences, Acoustic phonons, 010306 general physics, Acoustic modeling, Acoustic attenuation
Abstract: International audience; Nowadays metamaterials are at the focus of an intense research as promising for thermal and acoustic engineering. However, the computational cost associated to the large system size required for correctly simulating them imposes the use of finite-elements simulations, developing continuum models, able to grasp the physics at play without entering in the atomistic details. Still, a correct description should be able to reproduce not only the extrinsic scattering sources on waves propagation, as introduced by the metamaterial microstructure, but also the intrinsic wave attenuation of the material itself. This becomes dramatically important when the metamaterial is made out of a glass, which is intrinsically highly dissipative and with a wave attenuation strongly dependent on frequency. Here we propose a continuum mechanical model for a viscoelastic medium, able to bridge atomic and macroscopic scale in amorphous materials and describe phonon attenuation due to atomistic mechanisms, characterized by a defined frequency dependence. This represents a first decisive step for investigating the effect of a complex nano- or microstructure on acoustic attenuation, while including the atomistic contribution as well.
Published: 2020
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3. Neuromorphic spintronics

Author: J. Grollier, D. Querlioz, K. Y. Camsari, K. Everschor-Sitte, S. Fukami, M. D. Stiles, Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), THALES-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Centre National de la Recherche Scientifique (CNRS), Purdue University [West Lafayette], Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Tohoku University [Sendai], and National Institute of Standards and Technology [Gaithersburg] (NIST)
Subjects: Quantitative Biology::Neurons and Cognition, Neurosciences, 02 engineering and technology, Physik (inkl. Astronomie), 021001 nanoscience & nanotechnology, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 01 natural sciences, Article, Electronic, Optical and Magnetic Materials, Computer Science::Emerging Technologies, Affordable and Clean Energy, 0103 physical sciences, Electrical and Electronic Engineering, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, Instrumentation, ComputingMilieux_MISCELLANEOUS
Abstract: Neuromorphic computing uses basic principles inspired by the brain to design circuits that perform artificial intelligence tasks with superior energy efficiency. Traditional approaches have been limited by the energy area of artificial neurons and synapses realized with conventional electronic devices. In recent years, multiple groups have demonstrated that spintronic nanodevices, which exploit the magnetic as well as electrical properties of electrons, can increase the energy efficiency and decrease the area of these circuits. Among the variety of spintronic devices that have been used, magnetic tunnel junctions play a prominent role because of their established compatibility with standard integrated circuits and their multifunctionality. Magnetic tunnel junctions can serve as synapses, storing connection weights, functioning as local, nonvolatile digital memory or as continuously varying resistances. As nano-oscillators, they can serve as neurons, emulating the oscillatory behavior of sets of biological neurons. As superparamagnets, they can do so by emulating the random spiking of biological neurons. Magnetic textures like domain walls or skyrmions can be configured to function as neurons through their non-linear dynamics. Several implementations of neuromorphic computing with spintronic devices demonstrate their promise in this context. Used as variable resistance synapses, magnetic tunnel junctions perform pattern recognition in an associative memory. As oscillators, they perform spoken digit recognition in reservoir computing and when coupled together, classification of signals. As superparamagnets, they perform population coding and probabilistic computing. Simulations demonstrate that arrays of nanomagnets and films of skyrmions can operate as components of neuromorphic computers. While these examples show the unique promise of spintronics in this field, there are several challenges to scaling up, including the efficiency of coupling between devices and the relatively low ratio of maximum to minimum resistances in the individual devices.
Published: 2020
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4. 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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5. Enhancing domain wall velocity through interface intermixing in W-CoFeB-MgO films with perpendicular anisotropy

Author: Samridh Jaiswal, Carolyna Hepburn, Dafiné Ravelosona, Gianfranco Durin, Liza Herrera Diez, Mohamed Belmeguenai, Jürgen Langer, Boyu Zhang, Gerhard Jakob, N. Vernier, Xueying Zhang, Wang Lin, Berthold Ocker, Arianna Casiraghi, S. M. Chérif, Mamour Sall, Weisheng Zhao, Tao Xing, Mathias Kläui, Andrei A. Stashkevich, Yves Roussigné, Xiaoxuan Zhao, Beihang University (BUAA), Institut d'électronique fondamentale (IEF), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), College of Life Sciences, Huazhong University of Science and Technology [Wuhan] (HUST), Matériaux, Défauts et IRradiations (MADIR), Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut des Nanosciences de Paris (INSP), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Sciences des Procédés et des Matériaux (LSPM), Université Paris 13 (UP13)-Institut Galilée-Université Sorbonne Paris Cité (USPC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Propriétés Mécaniques et Thermodynamiques des Matériaux (LPMTM), Université Paris 13 (UP13)-Institut Galilée-Centre National de la Recherche Scientifique (CNRS), Singulus technology AG, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), Fert Beijing Institute and School of Electronic and Information Engineering, ANR-16-CE24-0018,ELECSPIN,Dispositifs Spintronique assistés par champ électrique(2016), Centre de Nanosciences et de Nanotechnologies (C2N), Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU), and Johannes Gutenberg - Universität Mainz (JGU)
Subjects: 010302 applied physics, Materials science, Physics and Astronomy (miscellaneous), Spintronics, Magnetic domain, Condensed matter physics, 530 Physics, Perpendicular magnetic anisotropy, 02 engineering and technology, 530 Physik, 021001 nanoscience & nanotechnology, 01 natural sciences, [SPI]Engineering Sciences [physics], Domain wall (magnetism), Creep, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], 0103 physical sciences, Perpendicular anisotropy, Irradiation, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 0210 nano-technology, Anisotropy, ComputingMilieux_MISCELLANEOUS
Abstract: We study the influence of He+ irradiation induced interface intermixing on magnetic domain wall (DW) dynamics in W-CoFeB (0.6 nm)-MgO ultrathin films, which exhibit high perpendicular magnetic anisotropy and large Dzyaloshinskii-Moriya interaction (DMI) values. Whereas the pristine films exhibit strong DW pinning, we observe a large increase in the DW velocity in the creep regime upon He+ irradiation, which is attributed to the reduction of pinning centers induced by interface intermixing. Asymmetric in-plane field-driven domain expansion experiments show that the DMI value is slightly reduced upon irradiation, and a direct relationship between DMI and interface anisotropy is demonstrated. Our findings provide insights into the material design and interface control for DW dynamics, as well as for DMI, enabling the development of high-performance spintronic devices based on ultrathin magnetic layers.
Published: 2019
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6. 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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7. Terahertz spectroscopy for all-optical spintronic characterization of the spin-Hall-effect metals Pt, W and Cu80Ir20

Author: Markus Münzenberg, Oliver Gueckstock, Vasily V. Temnov, Samridh Jaiswal, Lukas Nadvornik, Tom Seifert, Mathias Kläui, S.M. Rouzegar, Gerhard Jakob, Tobias Kampfrath, Martin Wolf, N.M. Tran, Institut des Molécules et Matériaux du Mans (IMMM), Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Fritz-Haber-Institut der Max-Planck-Gesellschaft (FHI), Max Planck Society, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Fachbereich Physik [Berlin], and Freie Universität Berlin
Subjects: Materials science, Acoustics and Ultrasonics, 530 Physics, terahertz emission spectroscopy, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Transition metal, Hall effect, 0103 physical sciences, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), ultrafast spincaloritronics, 010306 general physics, Spectroscopy, ComputingMilieux_MISCELLANEOUS, terahertz transmission spectroscopy, ultrafast spintronics, Condensed Matter - Materials Science, Spintronics, Condensed Matter - Mesoscale and Nanoscale Physics, business.industry, Relaxation (NMR), Refractory metals, Materials Science (cond-mat.mtrl-sci), 021001 nanoscience & nanotechnology, Condensed Matter Physics, 530 Physik, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 3. Good health, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Terahertz spectroscopy and technology, Spin Hall effect, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Optoelectronics, 0210 nano-technology, business
Abstract: Identifying materials with an efficient spin-to-charge conversion is crucial for future spintronic applications. In this respect, the spin Hall effect is a central mechanism as it allows for the interconversion of spin and charge currents. Spintronic material research aims at maximizing its efficiency, quantified by the spin Hall angle and the spin-current relaxation length . We develop an all-optical contact-free method with large sample throughput that allows us to extract and . Employing terahertz spectroscopy and an analytical model, magnetic metallic heterostructures involving Pt, W and Cu80Ir20 are characterized in terms of their optical and spintronic properties. The validity of our analytical model is confirmed by the good agreement with literature DC values. For the samples considered here, we find indications that the interface plays a minor role for the spin-current transmission. Our findings establish terahertz emission spectroscopy as a reliable tool complementing the spintronics workbench., Journal of Physics D: Applied Physics, 51 (36), ISSN:0022-3727, ISSN:1361-6463
Published: 2018
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8. Strongly correlated one-dimensional Bose–Fermi quantum mixtures: symmetry and correlations

Author: Matteo Rizzi, Anna Minguzzi, Johannes Jünemann, Patrizia Vignolo, Jean Decamp, Mathias Albert, Institut Non Linéaire de Nice Sophia-Antipolis (INLN), Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Institut de Physique de Nice (INPHYNI), Centre National de la Recherche Scientifique (CNRS)-Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Laboratoire de physique et modélisation des milieux condensés (LPM2C), Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Université Nice Sophia Antipolis (... - 2019) (UNS), and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Condensed Matter::Quantum Gases, [PHYS]Physics [physics], [PHYS.COND.GAS]Physics [physics]/Condensed Matter [cond-mat]/Quantum Gases [cond-mat.quant-gas], FOS: Physical sciences, General Physics and Astronomy, 01 natural sciences, Symmetry (physics), 010305 fluids & plasmas, Quantum Gases (cond-mat.quant-gas), Quantum mechanics, 0103 physical sciences, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, Condensed Matter - Quantum Gases, Quantum, ComputingMilieux_MISCELLANEOUS, Fermi Gamma-ray Space Telescope
Abstract: We consider multi-component quantum mixtures (bosonic, fermionic, or mixed) with strongly repulsive contact interactions in a one-dimensional harmonic trap. In the limit of infinitely strong repulsion and zero temperature, using the class-sum method, we study the symmetries of the spatial wave function of the mixture. We find that the ground state of the system has the most symmetric spatial wave function allowed by the type of mixture. This provides an example of the generalized Lieb-Mattis theorem. Furthermore, we show that the symmetry properties of the mixture are embedded in the large-momentum tails of the momentum distribution, which we evaluate both at infinite repulsion by an exact solution and at finite interactions using a numerical DMRG approach. This implies that an experimental measurement of the Tan's contact would allow to unambiguously determine the symmetry of any kind of multi-component mixture., 19 pages, 6 figures
Published: 2017
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9. Skyrmions in Magnetic Multilayers: Chirality, Electrical Detection and Current-induced Motion

Author: Carlos A. F. Vaz, Nicolas Jaouen, Vincent Cros, William Legrand, S. McFadzean, Jörg Raabe, Albert Fert, Sophie Collin, Karim Bouzehouane, Christoforos Moutafis, Karin Garcia, Nicolas Reyren, Horia Popescu, Simone Finizio, Stephen McVitie, Davide Maccariello, Jean-Yves Chauleau, Sean Hughes, Drouhin, Henri-Jean, Wegrowe, Jean-Eric, Razeghi, Manijeh, Jaffrès, Henri, Unité mixte de physique CNRS/Thales (UMPhy CNRS/THALES), Centre National de la Recherche Scientifique (CNRS)-THALES, Synchrotron SOLEIL (SSOLEIL), Centre National de la Recherche Scientifique (CNRS), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), University of Cambridge [UK] (CAM), Paul Scherrer Institute (PSI), THALES [France]-Centre National de la Recherche Scientifique (CNRS), Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), and European Project: 665095,H2020,H2020-FETOPEN-2014-2015-RIA,MAGicSky(2015)
Subjects: Materials science, metal, nucleation, 02 engineering and technology, domain wall, 01 natural sciences, spin torque, MFM, XRMS, Electrical resistivity and conductivity, 0103 physical sciences, Microscopy, Electrical measurements, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, Condensed matter physics, Scattering, multilayer, Skyrmion, STXM, 021001 nanoscience & nanotechnology, Domain wall (magnetism), skyrmion, Néel, Transmission electron microscopy, Magnetic force microscope, 0210 nano-technology
Abstract: International audience; Sub-100-nm skyrmions are stabilized in magnetic metallic multilayers and observed using transmission electron microscopy, magnetic force microscopy, scanning transmission X-ray microscopy and X-ray resonant magnetic scattering. All these advanced imaging techniques demonstrate the presence of "pure" Néel skyrmion textures with a determined chirality. Combining these observations with electrical measurements allows us to demonstrate reproducible skyrmion nucleation using current pulses, and measure their contribution to the transverse resistivity to detect them electrically. Once nucleated, skyrmions can be moved using charge currents. We find predominantly a creep-like regime, characterized by disordered skyrmion motion, as observed by atomic force microscopy and scanning transmission X-ray microscopy. These observations are explained qualitatively and to some extent quantitatively by the presence of crystalline grains of about 20 nm lateral size with a distribution of magnetic properties.
Published: 2017
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10. 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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11. 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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12. 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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13. High-momentum tails as magnetic structure probes for strongly-correlated SU(κ) fermionic mixtures in one-dimensional traps

Author: Decamp, Jean, Jünemann, Johannes, Albert, Mathias, Rizzi, Matteo, Minguzzi, Anna, Vignolo, Patrizia, Institut Non Linéaire de Nice Sophia-Antipolis (INLN), Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Université Côte d'Azur, CNRS, LPMC, France, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Laboratoire de physique et modélisation des milieux condensés (LPM2C), and Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])
Subjects: [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], PACS numbers: 05.30.-d,67.85.-d,67.85.Pq, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat]
Abstract: International audience; A universal k −4 decay of the large-momentum tails of the momentum distribution, fixed by Tan's contact coefficients, constitutes a direct signature of strong correlations in a short-range interacting quantum gas. Here we consider a repulsive multicomponent Fermi gas under harmonic confinement, as in the experiment of Pagano et al. [Nat. Phys. 10, 198 (2014)], realizing a gas with tunable SU (κ) symmetry. We exploit an exact solution at infinite repulsion to show a direct correspondence between the value of the Tan's contact for each of the κ components of the gas and the Young tableaux for the SN permutation symmetry group identifying the magnetic structure of the ground-state. This opens a route for the experimental determination of magnetic configurations in cold atomic gases, employing only standard (spin-resolved) time-of-flight techniques. Combining the exact result with matrix-product-states simulations, we obtain the Tan's contact at all values of repulsive interactions. We show that a local density approximation (LDA) on the Bethe-Ansatz equation of state for the homogeneous mixture is in excellent agreement with the results for the harmonically confined gas. At strong interactions, the LDA predicts a scaling behavior of the Tan's contact. This provides a useful analytical expression for the dependence on the number of fermions, number of components and on interaction strength. Moreover, using a virial approach, we study the Tan's contact behaviour at large temperatures and in the limit of infinite interactions and we show that it increases with the temperature and the number of components. At zero temperature, we predict that the weight of the momentum distribution tails increases with interaction strength and the number of components if the population per component is kept constant. This latter property was experimentally observed in Ref. [Nat. Phys. 10, 198 (2014)].
Published: 2016
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14. Electroburning of few-layer graphene flakes, epitaxial graphene, and turbostratic graphene discs in air and under vacuum

Author: Domenica Convertino, Nils Richter, Wolfgang Wernsdorfer, Franck Balestro, Marco Affronte, Andrea Candini, Camilla Coletti, Mathias Kläui, Istituto di Nanoscienze, CNR-S3, Circuits électroniques quantiques Alpes (QuantECA), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Institut für Physik [Mainz], and Johannes Gutenberg - Universität Mainz (JGU)
Subjects: Molecular spintronics, molecular spintronics, Materials science, molecular electronics, Molecular electronics, General Physics and Astronomy, Nanotechnology, lcsh:Chemical technology, Epitaxy, Graphene based electrodes, lcsh:Technology, Full Research Paper, Graphene, Materials Science (all), Electrical and Electronic Engineering, Physics and Astronomy (all), law.invention, law, lcsh:TP1-1185, ddc:530, General Materials Science, lcsh:Science, ComputingMilieux_MISCELLANEOUS, Graphene oxide paper, [PHYS]Physics [physics], lcsh:T, graphene based electrodes, Physics, Graphene foam, lcsh:QC1-999, Nanoscience, Electrode, lcsh:Q, Bilayer graphene, lcsh:Physics, Graphene nanoribbons
Abstract: Graphene-based electrodes are very promising for molecular electronics and spintronics. Here we report a systematic characterization of the electroburning (EB) process, leading to the formation of nanometer-spaced gaps, on different types of few-layer graphene (namely mechanically exfoliated graphene on SiO2, graphene epitaxially grown on the C-face of SiC and turbostratic graphene discs deposited on SiO2) under air and vacuum conditions. The EB process is found to depend on both the graphene type and on the ambient conditions. For the mechanically exfoliated graphene, performing EB under vacuum leads to a higher yield of nanometer-gap formation than working in air. Conversely, for graphene on SiC the EB process is not successful under vacuum. Finally, the EB is possible with turbostratic graphene discs only after the creation of a constriction in the sample using lithographic patterning.
Published: 2015
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15. 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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16. Spin-orbit torques for current parallel and perpendicular to a domain wall

Author: Tomek Schulz, Oscar Alejos, Eduardo Martinez, Kjetil M. D. Hals, Karin Garcia, Laurent Vila, Kyujoon Lee, Roberto Lo Conte, Gurucharan V. Karnad, Simone Moretti, Berthold Ocker, Dafiné Ravelosona, Arne Brataas, Mathias Kläui, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Universidad de Valladolid [Valladolid] (UVa), Universidad de Salamanca, Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Institut d'électronique fondamentale (IEF), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), 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), Singulus technology AG, Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU), European Project: 246102,EC:FP7:NMP,FP7-NMP-2009-LARGE-3,IFOX(2010), European Project: 208162,EC:FP7:ERC,ERC-2007-StG,MASPIC(2008), European Project: 608031,EC:FP7:PEOPLE,FP7-PEOPLE-2013-ITN,WALL(2013), European Project: 257707,EC:FP7:ICT,FP7-ICT-2009-5,MAGWIRE(2010), Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), and University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH)
Subjects: Physics, [PHYS]Physics [physics], Condensed Matter - Mesoscale and Nanoscale Physics, Physics and Astronomy (miscellaneous), Field (physics), Condensed matter physics, FOS: Physical sciences, Dynamics, Motion, Domain wall (magnetism), Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Line (geometry), Orbit (dynamics), Perpendicular, Torque, Current (fluid), Spin-½, Films
Abstract: We report field- and current-induced domain wall (DW) depinning experiments in Ta/Co20Fe60B20/MgO nanowires through a Hall cross geometry. While purely field-induced depinning shows no angular dependence on in-plane fields, the effect of the current depends crucially on the internal DW structure, which we manipulate by an external magnetic in-plane field. We show for the first time depinning measurements for a current sent parallel to the DW and compare its depinning efficiency with the conventional case of current flowing perpendicularly to the DW. We find that the maximum efficiency is similar for both current directions within the error bars, which is in line with a dominating damping-like spin-orbit torque (SOT) and indicates that no large additional torques arise for currents parallel to the DW. Finally, we find a varying dependence of the maximum depinning efficiency angle for different DWs and pinning levels. This emphasizes the importance of our full angular scans compared to previously used measurements for just two field directions (parallel and perpendicular to the DW) and shows the sensitivity of the spin-orbit torque to the precise DW structure and pinning sites., Comment: 11 pages, 3 figures
Published: 2015
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17. Spin relaxation in Cu and Al spin conduits

Author: Motzko, Nils, Richter, Nils, Burkhardt, Björn, Reeve, Robert, Laczkowski, Piotr, Vila, Laurent, Attané, Jean-Philippe, Kläui, Mathias, 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), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), and Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU)
Subjects: [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], ComputingMilieux_MISCELLANEOUS
Abstract: International audience
Published: 2014
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18. Domain wall transformations and hopping in La 0.7 Sr 0.3 MnO 3 nanostructures imaged with high resolution x-ray magnetic microscopy

Author: Finizio, S, Foerster, M, Kruger, B, Vaz, C. A., Miyawaki, T, Mawass, M., Peña, L, Méchin, Laurence, Huhn, Sebastian, Moshnyaga, V, Buttner, Félix, Bisig, A, Le Guyader, L, El Moussaoui, S., Valencia, S, Kronast, F, Eisebitt, S, Kläui, M, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), ALBA Synchrotron light source [Barcelone], Swiss FEL [Villigen], Paul Scherrer Institute (PSI), Nagoya University, Max Planck Institute for Intelligent Systems, Max-Planck-Gesellschaft, Equipe Electronique - Laboratoire GREYC - UMR6072, Groupe de Recherche en Informatique, Image et Instrumentation de Caen (GREYC), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU), Georg-August-University [Göttingen], Institut fur Optik und Atomare Physik, Technische Universität Berlin (TU), The Swiss Light Source (SLS) (SLS-PSI), and Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB)
Subjects: Condensed Matter::Materials Science, x-ray microscopy, LSMO, Condensed Matter::Strongly Correlated Electrons, current induced domain wall motion, [SPI.TRON]Engineering Sciences [physics]/Electronics
Abstract: International audience; We investigate the effect of electric current pulse injection on domain walls in La 0.7 Sr 0.3 MnO 3 (LSMO) half-ring nanostructures by high resolution x-ray magnetic microscopy at room temperature. Due to the easily accessible Curie temperature of LSMO, we can employ reasonable current densities to induce the Joule heating necessary to observe effects such as hopping of the domain walls between different pinning sites and nucleation/annihilation events. Such effects are the dominant features close to the Curie temperature, while spin torque is found to play a small role close to room temperature. We are also able to observe thermally activated domain wall transformations and we find that, for the analyzed geometries, the vortex domain wall configuration is energetically favored, in agreement with micromagnetic simulations.
Published: 2014

19. Efficient spin transfer torque in La2/3Sr1/3MnO3 nanostructures

Author: Michael Foerster, Mathias Kläui, Laurence Méchin, C. A. F. Vaz, Vasily Moshnyaga, Simone Finizio, Stefan Eisebitt, T. Schulz, Luis Peña, Felix Büttner, André Bisig, S. Hühn, Jan Heinen, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), ALBA Synchrotron light source [Barcelone], Swiss FEL [Villigen], Paul Scherrer Institute (PSI), Fachbereich Physik [Konstanz], University of Konstanz, Institut fur Optik und Atomare Physik, Technische Universität Berlin (TU), Equipe Electronique - Laboratoire GREYC - UMR6072, Groupe de Recherche en Informatique, Image et Instrumentation de Caen (GREYC), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU), and Georg-August-University [Göttingen]
Subjects: Permalloy, Materials science, Physics and Astronomy (miscellaneous), Condensed matter physics, Magnetoresistance, 530 Physics, Spin-transfer torque, 530 Physik, Magnetization, [SPI]Engineering Sciences [physics], Domain wall (magnetism), Torque, Condensed Matter::Strongly Correlated Electrons, ddc:530, Electric current, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Spin-½
Abstract: This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This material originally appeared in Appl. Phys. Lett. 104, 072410 (2014) and may be found at https://doi.org/10.1063/1.4865415. We carry out low temperature magnetotransport measurements on nanostructured La2/3Sr1/3MnO3 wires to study the interaction between spin-polarized current and magnetization in this half metallic material. We selectively position domain walls by applying external fields. The domain wall resistance is found to be positive, in contrast to conventional 3d metals. The depinning field is reduced when current pulses are injected into the wire. By comparing measurements for both current polarities, we can disentangle heating and spin transfer torque effects. The determined spin transfer torque efficiency is of the order of 4 × 10−14 Tm2/A, which is significantly higher than in permalloy.
Published: 2014
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20. The 2014 Magnetism Roadmap

Author: Bernard Dieny, Burkard Hillebrands, Gerrit E. W. Bauer, Jan Ulrich Thiele, Stephan Breitkreutz, Andrii V. Chumak, Martin Bowen, Mathias Kläui, Sara A. Majetich, Johan Åkerman, Robert Stamps, Ioan Lucian Prejbeanu, Nora Dempsey, Yoshichika Otani, SUPA School of Physics and Astronomy [Glasgow], University of Glasgow, Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), University of Gothenburg (GU), Fachbereich Physik [Kaiserslautern], Technische Universität Kaiserslautern (TU Kaiserslautern), Institute for Solid State Physics [Tokyo] (ISSP), The University of Tokyo (UTokyo), Institut für Halbleiter und Festkörperphysik, Johannes Kepler Universität, HGST San Jose Research Center, Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), Université de Strasbourg (UNISTRA)-Matériaux et nanosciences d'Alsace (FMNGE), Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA), Department of Physics [Pittsburgh], Carnegie Mellon University [Pittsburgh] (CMU), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), 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), Micro et NanoMagnétisme (MNM), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Matériaux et Nanosciences Grand-Est (MNGE), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Réseau nanophotonique et optique, Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), and Micro et NanoMagnétisme (NEEL - MNM)
Subjects: [PHYS]Physics [physics], Dynamic field, Random access memory, Condensed Matter - Materials Science, Materials science, Acoustics and Ultrasonics, Scope (project management), Condensed Matter - Mesoscale and Nanoscale Physics, Magnetism, New materials, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, Condensed Matter Physics, Field (computer science), Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Systems engineering
Abstract: Magnetism is a very fascinating and dynamic field. Especially in the last 30 years it has experienced many major advances in the full range from novel fundamental phenomena to new products. Applications such as hard disk drives and magnetic sensors are part of our daily life, and new applications, such as in non-volatile computer random access memory, are expected to surface shortly. Thus it is timely for describing the current status, and current and future challenges in the form of a Roadmap article. This 2014 Magnetism Roadmap provides a view on several selected, currently very active innovative developments. It consists of 12 sections, each written by an expert in the field and addressing a specific subject, with strong emphasize on future potential. This Roadmap cannot cover the entire field. We have selected several highly relevant areas without attempting to provide a full review - a future update will have room for more topics. The scope covers mostly nano-magnetic phenomena and applications, where surfaces and interfaces provide additional functionality. New developments in fundamental topics such as interacting nano-elements, novel magnon-based spintronics concepts, spin-orbit torques and spin-caloric phenomena are addressed. New materials, such as organic magnetic materials and permanent magnets are covered. New applications are presented such as nano-magnetic logic, non-local and domain-wall based devices, heat-assisted magnetic recording, magnetic random access memory, and applications in biotechnology. May the Roadmap serve as a guideline for future emerging research directions in modern magnetism., 37 pages
Published: 2014
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21. Measurement of the Neutron Electric to Magnetic Form Factor Ratio at Q2=1.58 GeV2 Using the Reaction He−→3(e⃗ ,e′n)pp

Author: Schlimme, B.S., Achenbach, P., Ayerbe Gayoso, C. A., Bernauer, J. C., Böhm, R., Bosnar, D., Challand, T., Distler, M.O., Doria, L., Fellenberger, F., Fonvieille, H., Gómez Rodríguez, M., Grabmayr, P., Hehl, T., Heil, W., Kiselev, D., Krimmer, J., Makek, M., Merkel, H., Middleton, D. G., Müller, U., Nungesser, L., Ott B., A., Pochodzalla, J., Potokar, M., Sánchez Majos, S., Sargsian M., M., Sick, I., Širca, S., Weinriefer, M., Wendel, M., Yoon, J., Institut für Kernphysik, Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), Department of Physics [Zagreb], Faculty of Science [Zagreb], University of Zagreb-University of Zagreb, Department of Physics, University of Basel (Unibas), Laboratoire de Physique Corpusculaire - Clermont-Ferrand (LPC), Université Blaise Pascal - Clermont-Ferrand 2 (UBP)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Physikalisches Institut [Tübingen], Eberhard Karls Universität Tübingen = Eberhard Karls University of Tuebingen, Institut für Physik [Mainz], The Swiss Light Source (SLS) (SLS-PSI), Paul Scherrer Institute (PSI), Institut de Physique Nucléaire de Lyon (IPNL), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Jozef Stefan Institute [Ljubljana] (IJS), Florida International University [Miami] (FIU), University of Ljubljana, Johannes Gutenberg - Universität Mainz (JGU), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)
Subjects: High Energy Physics::Experiment, Nuclear Experiment
Abstract: International audience; A measurement of beam helicity asymmetries in the reaction He−→3(e⃗ ,e′n)pp is performed at the Mainz Microtron in quasielastic kinematics to determine the electric to magnetic form factor ratio of the neutron GnE/GnM at a four-momentum transfer Q2=1.58 GeV2. Longitudinally polarized electrons are scattered on a highly polarized He3 gas target. The scattered electrons are detected with a high-resolution magnetic spectrometer, and the ejected neutrons are detected with a dedicated neutron detector composed of scintillator bars. To reduce systematic errors, data are taken for four different target polarization orientations allowing the determination of GnE/GnM from a double ratio. We find μnGnE/GnM=0.250±0.058(stat)±0.017(syst).
Published: 2013
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22. First measurement of the helicity dependence of 3He photoreactions in the Δ(1232)Δ(1232) resonance region

Author: Bartolomé P., A., Mushkarenkov, A., Ahrens, J., Annand, J.R.M., Arends, H.-J., Beck, R., Bekrenev, V., Berghäuser, H., Braghieri, A., Briscoe, W. J., Cherepnya S., N., Costanza, S., Drexler, P., Filʼkov L., V., Fix, A., Giardina, G., Glazier, D. I., Hamilton, D., Heid, E., Heil, W., Hornidge, D., Howdle, D., Jaegle, I., Jahn, O., Jude, T., Kashevarov V., L., Keshelashvili, I., Kondratiev, R., Korolija, M., Krimmer, J., Krusche, B., Kruglov, S., Kulbardis, A., Lisin, M., Livingston, K., Mancell, J., Middleton D., G., MacGregor, I. J. D., Manley, D.M., Mcgeorge, J.C., Metag, V., Nefkens, B.M.K., Nikolaev, A., Oberle, M., Ostrick, M., Ortega, H., Otte, P.B., Oussena, B., Pedroni, P., Pheron, F., Institut für Kernphysik, Johannes Gutenberg - Universität Mainz (JGU), Istituto Nazionale di Fisica Nucleare, Sezione di Pavia (INFN), Istituto Nazionale di Fisica Nucleare (INFN), SUPA School of Physics and Astronomy [Glasgow], University of Glasgow, Helmholtz-Institut für Strahlen- und Kernphysik (HISKP), Rheinische Friedrich-Wilhelms-Universität Bonn, Petersburg Nuclear Physics Institute, Kurchatov Institute, Physikalisches Institut [Gießen], Justus-Liebig-Universität Gießen (JLU), Department of Physics, The George Washington University (GW), P. N. Lebedev Physical Institute of the Russian Academy of Sciences [Moscow] (LPI RAS), Russian Academy of Sciences [Moscow] (RAS), Department of Higher Mathematics and Mathematical Physics, Tomsk Polytechnic University [Russie] (UPT), Dipartimento di Fisica e Scienze della Terra [Messina], Universita degli Studi di Messina, Institut für Physik [Mainz], Mount Allison University, Institut für Physik, University of Basel (Unibas), Institute for Nuclear Research, Rudjer Boskovic Institute [Zagreb], Institut de Physique Nucléaire de Lyon (IPNL), Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Kent State University, University of California [Los Angeles] (UCLA), and University of California
Subjects: Nuclear Theory, Nuclear Experiment
Abstract: International audience; The first measurement of the helicity dependence of the total inclusive 3He photo-absorption cross section and of the partial cross sections for several reaction channels was carried out at MAMI (Mainz) in the photon energy range between 150 and 500 MeV. The experiment used the large acceptance Crystal Ball spectrometer, complemented by charged particle and vertex detectors, a circularly polarised tagged photon beam and a longitudinally polarised high-pressure 3He gas target. The results obtained give information on the GDH integral on 3He and on the neutron and allow an investigation of the modifications of nucleon properties inside 3He.
Published: 2013
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23. Non-Newton Man: An exploration of magmatic shear thinning sources

Author: Cordonnier, Benoit, Manga, Michael, Forien, Mélanie, Kauss, Boris, Yamato, Philippe, Duretz, Thibault, Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), Systèmes Tectoniques, Géosciences Rennes (GR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Université de Lausanne = University of Lausanne (UNIL), University of California [Berkeley], University of California-University of California, Johannes Gutenberg - Universität Mainz (JGU), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), and Université de Lausanne (UNIL)
Subjects: Physics::Fluid Dynamics, [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography
Abstract: International audience; Natural magmas display at different levels a viscosity dependency with the stress. This non-Newtonian behavior often come off as a decrease of the measured apparent viscosity or shear thinning. However the shear thinning sources, necessary to scale back the flow behavior to natural scales, are poorly constrained. If a few hypothesis have been proposed, none have yet stood up or been clearly quantified. For pure melts we already demonstrated that Non-Newtonian behaviors simply result from viscous heating. With this study we investigate several potential sources to explain the decrease of viscosity in crystal bearing systems. If most of our arguments are based on literature, a rheological characterization of rigid particles suspensions has been performed with a cone and plate rheoscope and is here used as reference. We present various theoretical limits of the potential sources cited in literature for shear thinning (viscous heating, particle migration and crystal breakage) and compare them to experimental results. The reference system does not allow crystal breakage and so remove this potential source for the effect measured in our experiments. Additionally, numerical simulations are presented to theoretically support the simpler models presented. They are based on elementary lattices and display the variation of local and bulk viscosity for rigid or deformable particles. We first discuss spherical particles suspensions and extend it next to various eccentricities. Finally numerical simulations are presented to theoretically confirm the suggested processes. From these results the sources of Non- Newtonian effects may results from only two effects. The first commonly mentioned in literature is a layering of particles for which we fix for the first time the limits. The second is a violation of volume conservation where the model is here presented for the first time. These observations conclude on the present problems linked to experimental design and the necessity to rethink rheological and viscosity measurements for magmas. Only better constrained apparatus will allow to fully understand Non-Newtonian behaviors and make possible the scaling to Earth like systems.
Published: 2013

24. Imaging current induced magnetic domain wall motion in La0.7Sr0.3MnO3 nanowires by XMCD-PEEM

Author: Foerster, M., Vaz, C.A.F., Pena, Luisa, Finizio, Simone, Méchin, Laurence, Mawass, M., Bisig, A., Büttner, Fabian, Kläui, M., Référent, Greyc, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), ALBA Synchrotron light source [Barcelone], Swiss FEL [Villigen], Paul Scherrer Institute (PSI), Equipe Electronique - Laboratoire GREYC - UMR6072, Groupe de Recherche en Informatique, Image et Instrumentation de Caen (GREYC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Fachbereich Physik [Konstanz], University of Konstanz, Modeling Technologies for Software Production, Operation, and Evolution (ATLANMOD), Laboratoire d'Informatique de Nantes Atlantique (LINA), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Département informatique - EMN, Mines Nantes (Mines Nantes)-Inria Rennes – Bretagne Atlantique, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS), Johannes Gutenberg - Universität Mainz (JGU), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU), Centre National de la Recherche Scientifique (CNRS)-Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Centre National de la Recherche Scientifique (CNRS)-Mines Nantes (Mines Nantes)-Université de Nantes (UN)-Département informatique - EMN, and Centre National de la Recherche Scientifique (CNRS)-Mines Nantes (Mines Nantes)-Université de Nantes (UN)
Subjects: [SPI]Engineering Sciences [physics], stomatognathic diseases, [SPI] Engineering Sciences [physics], health care facilities, manpower, and services, [SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, education, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, health care economics and organizations
Abstract: Présentation orale; International audience
Published: 2013

25. The effect of magnetic anisotropy on the spin configurations of patterned La0:7Sr0:3MnO3 elements

Author: Wohlhüter, P., Rhensius, J., Vaz, C.A.F., Heidler, J., Körner, H.S., Bisig, A., Foerster, M., Méchin, Laurence, Gaucher, F., Locatelli, A., Nino, M.A., Moussaoui, S. El, Nolting, F., Goering, E., Heyderman, L.J., Kläui, M., Swiss FEL [Villigen], Paul Scherrer Institute (PSI), Fachbereich Physik [Konstanz], University of Konstanz, Laboratoire de Traitement du signal [EPFL] / Signal Processing Laboratories (SP Lab), Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Equipe Electronique - Laboratoire GREYC - UMR6072, Groupe de Recherche en Informatique, Image et Instrumentation de Caen (GREYC), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU), Elettra Sincrotrone Trieste, The Swiss Light Source (SLS) (SLS-PSI), Max Planck Institute for Intelligent Systems, Max-Planck-Gesellschaft, Laboratory for Mesoscopic Systems [ETH Zürich], and Référent, Greyc
Subjects: Condensed Matter::Materials Science, [SPI]Engineering Sciences [physics], [SPI] Engineering Sciences [physics], 530 Physics, [SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 530 Physik
Abstract: International audience; We study the effect of magnetocrystalline anisotropy on the magnetic configurations of La0:7Sr0:3MnO3 bar and triangle elements using photoemission electron microscopy imaging. The dominant remanent state is a low energy flux-closure state for both thin (15 nm) and thick (50 nm) elements. The magnetocrystalline anisotropy, which competes with the dipolar energy, causes a strong modification of the spin configuration in the thin elements, depending on the shape, size and orientation of the structures. We investigate the magnetic switching processes and observe in triangular shaped elements a displacement of the vortex core along the easy axis for an external magnetic field applied close to the hard axis, which is well reproduced by micromagnetic simulations.
Published: 2013

26. Control of the magnetization in pre-patterned half-metallic La0.7Sr0.3MnO3 nanostructures

Author: H. S. Körner, Frithjof Nolting, Mathias Kläui, Sebastian Schweitzer, C. A. F. Vaz, T. O. Menteş, Laurence Méchin, Phillip Wohlhüter, Alan Farhan, Miguel Angel Niño, Jan Rhensius, J. Heidler, L. Le Guyader, Laura J. Heyderman, Florian Kronast, André Bisig, Andrea Locatelli, The Swiss Light Source (SLS) (SLS-PSI), Paul Scherrer Institute (PSI), Swiss FEL [Villigen], Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, Fachbereich Physik [Konstanz], University of Konstanz, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Equipe Electronique - Laboratoire GREYC - UMR6072, Groupe de Recherche en Informatique, Image et Instrumentation de Caen (GREYC), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU), Elettra Sincrotrone Trieste, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH (HZB), and Référent, Greyc
Subjects: Materials science, [SPI] Engineering Sciences [physics], 530 Physics, [SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, Magnetization, Condensed Matter::Materials Science, [SPI]Engineering Sciences [physics], Nuclear magnetic resonance, 0103 physical sciences, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 010302 applied physics, Magnetic structure, Condensed matter physics, Magnetic circular dichroism, 021001 nanoscience & nanotechnology, 530 Physik, Magnetic field, Amorphous solid, Magnetic anisotropy, Photoemission electron microscopy, Domain wall (magnetism), Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology
Abstract: International audience; The evolution of the magnetization configurations in highly spin polarized La0:7Sr0:3MnO3 (LSMO) thin film elements (20-60 nm in thickness) as a function of external magnetic field and temperature is studied by direct magnetic imaging using x-ray magnetic circular dichroism photoemission electron microscopy. The sample structuring is done via a pre-patterning process using a Cr mask layer. The LSMO grows amorphous on the Cr layer for the 20 nm thick film but polycrystalline at larger thicknesses. Temperature dependent studies allow for a direct comparison of the properties of the strained and unstrained LSMO regions on a single sample and show that the polycrystalline areas exhibit a higher TC compared to the epitaxial areas. The single crystalline areas are largely magnetically decoupled from the matrix. The magnetic switching between domain states and domain wall spin structures is determined for LSMO ring elements of varying size and thickness. We find that the magnetic field values required to depin domain walls or to nucleate domains increase with decreasing ring width due to the increasing role of shape anisotropy and edge defects. Both transverse and vortex domain walls are stable spin configurations at room temperature and at zero field. In particular, we demonstrate that the desired domain wall type can be selected by applying an appropriate field sequence.
Published: 2012

27. 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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28. In situ observations of new particle formation in the tropical upper troposphere: the role of clouds and the nucleation mechanism

Author: G. V. Belyaev, Cornelius Schiller, E.R. Lovejoy, J. M. Reeves, Stephan Borrmann, W. Frey, G. Shur, M. de Reus, Francesco Cairo, Ralf Weigel, Silvia Viciani, Hans Schlager, Daniel Kunkel, Kathy S. Law, Joachim Curtius, James C. Wilson, Andreas Minikin, C. M. Volk, Jan Kazil, Francesco D'Amato, Andreas Stohl, Thomas Peter, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Max-Planck-Institut für Chemie (MPIC), Max-Planck-Gesellschaft, NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt [Oberpfaffenhofen-Wessling] (DLR), Norwegian Institute for Air Research (NILU), Department of Mechanical and Materials Engineering [Denver], University of Denver, Department of Physics, Faculty of Mathematics und Natural Sciences [Wuppertal], University of Wuppertal, Istituto Nazionale di Ottica (INO), Consiglio Nazionale delle Ricerche (CNR), Institut für Energie- und Klimaforschung - Stratosphäre (IEK-7), Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association-Helmholtz-Gemeinschaft = Helmholtz Association, Institute for Atmospheric and Climate Science [Zürich] (IAC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), CNR Institute of Atmospheric Sciences and Climate (ISAC), 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), Central Aerological Observatory (CAO), Russian Federal Service for Hydrometeorology and Environmental Monitoring (Roshydromet), Myasishchev Design Bureau (MDB), Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), and National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR)
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, DISPERSION MODEL FLEXPART, aerosol, nucleation, Nucleation, clouds, 010502 geochemistry & geophysics, Atmospheric sciences, 01 natural sciences, tropics, Troposphere, lcsh:Chemistry, new particle formation, ddc:550, Cloud condensation nuclei, Life Science, Stratosphere, 0105 earth and related environmental sciences, Geophysica, [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, Ice cloud, Atmosphärische Spurenstoffe, Falcon, lcsh:QC1-999, Aerosol, AQUEOUS SULFURIC-ACID, lcsh:QD1-999, 13. Climate action, Climatology, upper troposphere, Environmental science, Outflow, AEROSOL NUCLEATION, LOWER STRATOSPHERE, Tropopause, lcsh:Physics, GALACTIC COSMIC-RAYS
Abstract: New particle formation (NPF), which generates nucleation mode aerosol, was observed in the tropical Upper Troposphere (UT) and Tropical Tropopause Layer (TTL) by in situ airborne measurements over South America (January–March 2005), Australia (November–December 2005), West Africa (August 2006) and Central America (2004–2007). Particularly intense NPF was found at the bottom of the TTL. Measurements with a set of condensation particle counters (CPCs) with different dp50 (50% lower size detection efficiency diameter or "cut-off diameter") were conducted on board the M-55 Geophysica in the altitude range of 12.0–20.5 km and on board the DLR Falcon-20 at up to 11.5 km altitude. On board the NASA WB-57F size distributions were measured over Central America in the 4 to 1000 nm diameter range with a system of nucleation mode aerosol spectrometers. Nucleation mode particle concentrations (NNM) were derived from these measurements which allow for identifying many NPF events with NNM in the range of thousands of particles per cm3. Over Australia and West Africa, we identified NPF in the outflow of tropical convection, in particular of a Mesoscale Convective System (MCS). Newly formed particles with NNM > 1000 cm−3 were found to coexist with ice cloud particles (dp > 2 μm) as long as cloud particle concentrations remained below 2 cm−3. The occurrence of NPF within the upper troposphere and the TTL was generally confined within 340 K to 380 K potential temperature, but NPF was of particular strength between 350 K and 370 K (i.e. ~1–4 km below the cold point tropopause). Analyses of the aerosol volatility (at 250 °C) show that in the TTL on average 75–90% of the particles were volatile, compared to typically only 50% in the extra-tropical UT, indicative for the particles to mainly consist of H2SO4-H2O and possibly organic compounds. Along two flight segments over Central and South America (24 February 2005 and 7 August 2006, at 12.5 km altitude) in cloud free air, above thin cirrus, particularly high NNM were observed. Recent lifting had influenced the probed air masses, and NNM reached up to 16 000 particles cm−3 (ambient concentration). A sensitivity study using an aerosol model, which includes neutral and ion induced nucleation processes, simulates NNM in reasonable agreement with the in situ observations of clear-air NPF. Based on new, stringent multi-CPC criteria, our measurements corroborate the hypothesis that the tropical UT and the TTL are regions supplying freshly nucleated particles. Our findings narrow the altitude of the main source region to the bottom TTL, i.e. to the level of main tropical convection outflow, and, by means of measurements of carbon monoxide, they indicate the importance of anthropogenic emissions in NPF. After growth and/or coalescence the nucleation mode particles may act as cloud condensation nuclei in the tropical UT, or, upon ascent into the stratosphere, contribute to maintain the stratospheric background aerosol.
Published: 2011
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29. Magnetic domain configuration of La0.7Sr0.3MnO3 patterned elements

Author: Vaz, C.A.F., Rhensius, J., Bisig, A., Kläui, M., Heyderman, Laura J, Nino, M.A., Locatelli, A., Gaucher, Fabien, Galdi, Alice, Méchin, Laurence, Référent, Greyc, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Swiss FEL [Villigen], Paul Scherrer Institute (PSI), Fachbereich Physik [Konstanz], University of Konstanz, Laboratory for Micro- and Nanotechnology, Paul Scherrer Institut, Elettra Sincrotrone Trieste, Equipe Electronique - Laboratoire GREYC - UMR6072, Groupe de Recherche en Informatique, Image et Instrumentation de Caen (GREYC), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)
Subjects: [SPI]Engineering Sciences [physics], [SPI] Engineering Sciences [physics], [SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, ComputingMethodologies_GENERAL, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, ComputingMilieux_MISCELLANEOUS
Abstract: The magnetization configuration in small La0.7Sr0.3MnO3 elements is investigated as a function of geometry, film thickness, magnetic field, and temperature using x-ray magnetic circular dichroism photoemission electron microscopy (XMCD-PEEM). The patterned elements were defined by focused ion beam (FIB) lithography, and consist of elements varying in shape (from circular, triangular and quadrangular) and size, from 200 nm up to 10 μm. A strong magnetic contrast is observed for all thicknesses (10-50 nm). The magnetic state in the larger elements tends to be multidomain, with complex configurations that are determined by the presence of local pinning sites. These pinning sites are overcome with increasing temperature, and the magnetic configuration evolves into lower energy states. In contrast, the magnetic configuration of the smaller elements are largely determined by the magnetostatic energy contribution, which gives rise to highly symmetric states as found in 3d ferromagnetic structures. Our results show that the magnetism of small LSMO elements is robust nearly up to the critical temperature, with magnetic configurations that can be controlled by suitable geometrical design.
Published: 2011

30. Depletion of the excited state population in negative ions using laser photodetachment in a gas-filled RF quadrupole ion guide

Author: Oliver Forstner, Anton Lindahl, Charles C Havener, Yuan Liu, Klaus Wendt, T. Gottwald, N. D. Gibson, Dag Hanstorp, Department of Physics [Gothenburg], University of Gothenburg (GU), Faculty of Physics [Vienna], Universität Wien, Department of Physics and Astronomy [Granville, OH], Denison University, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Physics Division [Oak Ridge], Oak Ridge National Laboratory [Oak Ridge] (ORNL), and UT-Battelle, LLC-UT-Battelle, LLC
Subjects: Physics, education.field_of_study, Population, chemistry.chemical_element, Condensed Matter Physics, Laser, 01 natural sciences, 7. Clean energy, Atomic and Molecular Physics, and Optics, law.invention, Ion, 010309 optics, chemistry, law, Excited state, 0103 physical sciences, Quadrupole, Physical Sciences, Laser power scaling, Atomic physics, 010306 general physics, Ground state, education, Helium
Abstract: International audience; The depopulation of excited states in beams of negatively charged carbon and silicon ions was demonstrated using collisional detachment and laser photodetachment in a radio frequency quadrupole ion guide filled with helium. The high lying, loosely bound 2 D excited state in C − was completely depleted through collisional detachment alone, which was quantitatively determined within 6%. For Si − the combined signal from the population in the 2 P and 2 D excited states was only partly depleted through collisions in the cooler. The loosely bound 2 P state was likely to be completely depopulated and the more tightly bound 2 D state was partly depopulated through collisions. 98(2)% of the remaining 2 D population was removed by photodetachment in the cooler using less than 2 W laser power. The total reduction of the excited population in Si −, including collisional detachment and photodetachment, was estimated to be 99(1)%. Employing this novel technique to produce a pure ground state negative ion beam offers possibilities to enhance selectivity, as well as accuracy, in high precision experiments on atomic as well as molecular negative ions.
Published: 2010
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31. Probe molecules in polymer melts near the glass transition: A molecular dynamics study of chain length effects

Author: Renaud A. L. Vallée, Wolfgang Paul, Kurt Binder, Centre de recherches Paul Pascal (CRPP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Martin-Luther-Universität Halle-Wittenberg, Martin-Luther-Universität Halle Wittenberg (MLU), Institut für Physik [Mainz], and Johannes Gutenberg - Universität Mainz (JGU)
Subjects: Incoherent scatter, General Physics and Astronomy, Linear dichroism, polymer melts, 01 natural sciences, Molecular dynamics, Computational chemistry, 0103 physical sciences, dichroism, glass transition, Physical and Theoretical Chemistry, 010306 general physics, chemistry.chemical_classification, 61.25.hk, 61.20.Ja, 78.55.Bq,78.20.Fm,64.70.pm, 010304 chemical physics, Polymer, [CHIM.MATE]Chemical Sciences/Material chemistry, vitrification, liquid theory, Condensed Matter::Soft Condensed Matter, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, molecular dynamics method, chemistry, 78.20.Fm Birefringence, Chemical physics, 64.70.pm Liquids, Cage effect, Dumbbell, Center of mass, fluorescence, Glass transition, liquid structure
Abstract: 9 pages; International audience; Molecular dynamics simulations of a dense melt of short bead-spring polymer chains containing N = 5, 10, or 25 effective monomers are presented and analyzed. Parts of our simulations include also a single dumbbell (N = 2) of the same type, which is interpreted to represent a coarse-grained model for a fluorescent probe molecule as used in corresponding experiments. We obtain the mean-square displacements of monomers and chains center of mass, and intermediate incoherent scattering functions of both monomers in the chains and particles in the dumbbells as function of time for a broad regime of temperatures above the critical temperature Tc of mode-coupling theory. For both the chains and the dumbbell, also orientational autocorrelation functions are calculated and for the dumbbell time series for the time evolution of linear dichroism and its autocorrelation function are studied. From both sets of data we find that both the mode-coupling critical temperature Tc (representing the “cage effect”) and the Vogel–Fulcher temperature T0 (representing the caloric glass transition temperature) systematically increase with chain length. Furthermore, the dumbbell dynamics yields detailed information on the differences in the matrix dynamics that are caused by the chain length variation. Deviations from the Stokes–Einstein relation are discussed, and an outlook to related experiments is given.
Published: 2010
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32. Single Molecules Probing the Freezing of Polymer Melts: A Molecular Dynamics Study for Various Molecule-Chain Linkages

Author: Renaud A. L. Vallée, Wolfgang Paul, Kurt Binder, Centre de recherches Paul Pascal (CRPP), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Martin-Luther-Universität Halle-Wittenberg, Martin-Luther-Universität Halle Wittenberg (MLU), Institut für Physik [Mainz], and Johannes Gutenberg - Universität Mainz (JGU)
Subjects: Polymers and Plastics, Single Molecules, 02 engineering and technology, Matrix (biology), Molecular dynamics, 010402 general chemistry, 01 natural sciences, Inorganic Chemistry, [PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], Chain (algebraic topology), Materials Chemistry, Molecule, chemistry.chemical_classification, Quantitative Biology::Biomolecules, Chemistry, Organic Chemistry, Polymer, 021001 nanoscience & nanotechnology, Fluorescence, 0104 chemical sciences, Condensed Matter::Soft Condensed Matter, Chemical physics, Physical chemistry, 0210 nano-technology, Glass transition
Abstract: 8 pages; International audience; We present molecular dynamics simulations of coarse-grained model systems of a glassforming polymer matrix containing fluorescent probe molecules. These probe molecules are either dispersed in the matrix or covalently attached to the center or the end of a dilute fraction of the polymer chains. We show that in all cases the translational and rotational relaxation of the probe molecules is a faithful sensor for the glass transition of the matrix as determined from a mode-coupling analysis or Vogel-Fulcher analysis of their R-relaxation behavior. Matrix and dumbbell related relaxation processes show a clear violation of the Stokes-Einstein-Debye laws. In accordance with recent experimental results, the long time behavior of single molecule spectroscopy observables like the linear dichroism is not susceptible to distinguish between center-attached and end-attached fluorophores. However we show that it is different from the behavior of dispersed fluorophores. We also show that the difference between the two attachment forms does show up in the caging regime of the relaxation functions and that this difference increases upon supercooling the melt toward its glass transition.
Published: 2010
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33. Zero-temperature responses of a 3D spin glass in a magnetic field

Author: Florent Krzakala, J. Houdayer, Olivier C. Martin, Enzo Marinari, Giorgio Parisi, Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Max-Planck-Institut für Polymerforschung (MPI-P), Max-Planck-Gesellschaft, Istituto Nazionale di Fisica Nucleare [Sezione di Roma 1] (INFN), Istituto Nazionale di Fisica Nucleare, and Le Vaou, Claudine
Subjects: Physics, Spin glass, Condensed matter physics, Spin polarization, General Physics and Astronomy, Energy landscape, Zero field splitting, 01 natural sciences, Condensed Matter::Disordered Systems and Neural Networks, [PHYS.COND.CM-DS-NN] Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], 010305 fluids & plasmas, Magnetic field, Paramagnetism, Lattice (order), 0103 physical sciences, Spin Hall effect, Condensed Matter::Strongly Correlated Electrons, [PHYS.COND.CM-DS-NN]Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], Disordered Systems and Neural Networks, 010306 general physics
Abstract: We probe the energy landscape of the 3D Edwards-Anderson spin glass in a magnetic field to test for a spin glass ordering. We find that the spin glass susceptibility is anomalously large on the lattice sizes we can reach. Our data suggest that a transition from the spin glass to the paramagnetic phase takes place at ${B}_{c}\ensuremath{\approx}0.65$, though the possibility ${B}_{c}\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}0$ cannot be excluded. We also discuss the question of the nature of the putative frozen phase.
Published: 2001

34. A hierarchical approach for computing spin glass ground states

Author: Jérôme Houdayer, Olivier C. Martin, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)
Subjects: Physics, Spin glass, FOS: Physical sciences, Population based, Disordered Systems and Neural Networks (cond-mat.dis-nn), Condensed Matter - Disordered Systems and Neural Networks, 01 natural sciences, 010305 fluids & plasmas, Quantum mechanics, 0103 physical sciences, Statistical physics, [PHYS.COND.CM-DS-NN]Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], Disordered Systems and Neural Networks, 010306 general physics, Reliability (statistics)
Abstract: We describe a numerical algorithm for computing spin glass ground states with a high level of reliability. The method uses a population based search and applies optimization on multiple scales. Benchmarks are given leading to estimates of the performance on large lattices., Comment: 8 pages, 3 figures, RevTex format
Published: 2001

35. Large-scale low-energy excitations in 3-d spin glasses

Author: Houdayer, J., Krzakala, F., Martin, O. C., Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz (JGU), Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS), and Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11)
Subjects: FOS: Physical sciences, Disordered Systems and Neural Networks (cond-mat.dis-nn), [PHYS.COND.CM-DS-NN]Physics [physics]/Condensed Matter [cond-mat]/Disordered Systems and Neural Networks [cond-mat.dis-nn], Condensed Matter - Disordered Systems and Neural Networks
Abstract: We numerically extract large-scale excitations above the ground state in the 3-dimensional Edwards-Anderson spin glass with Gaussian couplings. We find that associated energies are O(1), in agreement with the mean field picture. Of further interest are the position-space properties of these excitations. First, our study of their topological properties show that the majority of the large-scale excitations are sponge-like. Second, when probing their geometrical properties, we find that the excitations coarsen when the system size is increased. We conclude that either finite size effects are very large even when the spin overlap q is close to zero, or the mean field picture of homogeneous excitations has to be modified., 11 pages, typos corrected, added references
Published: 2000

36. 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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37. 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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38. 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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39. 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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40. 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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41. 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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42. Effective field analysis using the full angular spin-orbit torque magnetometry dependence

Author: Benjamin Krüger, Gurucharan V. Karnad, Kyujoon Lee, Laurent Vila, Roberto Lo Conte, Dafiné Ravelosona, Mathias Kläui, Karin Garcia, T. Schulz, Berthold Ocker, Institut für Physik [Mainz], Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), Institut d'électronique fondamentale (IEF), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), 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), Singulus technology AG, European Project: 665672,H2020,ERC-2014-PoC,MultiRev(2016), European Project: 608031,EC:FP7:PEOPLE,FP7-PEOPLE-2013-ITN,WALL(2013), European Project: 709151,H2020,H2020-MSCA-IF-2015,Standard EF(2016), and Johannes Gutenberg - Universität Mainz (JGU)
Subjects: Physics, Condensed matter physics, Magnetic domain, Condensed Matter - Mesoscale and Nanoscale Physics, Magnetometer, Dynamics (mechanics), FOS: Physical sciences, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, Magnetization, law, Harmonics, 0103 physical sciences, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Quasiparticle, Torque, Astrophysics::Earth and Planetary Astrophysics, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, ComputingMilieux_MISCELLANEOUS, Spin-½
Abstract: Spin-orbit torques promise ultra-efficient magnetization switching used for advanced devices based on emergent quasi-particles such as domain walls and skyrmions. Recently, the spin structure dynamics, materials and systems with tailored spin-orbit torques are being developed. A method, which allows one to detect the acting torques in a given system as a function of the magnetization direction is the torque-magnetometry method based on a higher harmonics analysis of the anomalous Hall-effect. Here we show that the effective fields acting on magnetic domain walls that govern the efficiency of their dynamics require a sophisticated analysis taking into account the full angular dependence of the torques. Using a 1-D model we compared the spin orbit torque efficiencies by depinning measurements and spin torque magnetometry. We show that the effective fields can be accurately determined and we find good agreement. Thus our method allows us now to rapidly screen materials and predict the resulting quasi-particle dynamics., Comment: 15 page, 3 figures
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43. First Offline Results from the S3 Low-Energy Branch

Author: Jekabs Romans, Anjali Ajayakumar, Martial Authier, Frederic Boumard, Lucia Caceres, Jean-François Cam, Arno Claessens, Samuel Damoy, Pierre Delahaye, Philippe Desrues, Antoine Drouart, Patricia Duchesne, Rafael Ferrer, Xavier Fléchard, Serge Franchoo, Patrice Gangnant, Ruben P. de Groote, Sandro Kraemer, Nathalie Lecesne, Renan Leroy, Julien Lory, Franck Lutton, Vladimir Manea, Yvan Merrer, Iain Moore, Alejandro Ortiz-Cortes, Benoit Osmond, Julien Piot, Olivier Pochon, Blaise-Maël Retailleau, Hervé Savajols, Simon Sels, Emil Traykov, Juha Uusitalo, Christophe Vandamme, Marine Vandebrouck, Paul Van den Bergh, Piet Van Duppen, Matthias Verlinde, Elise Verstraelen, Klaus Wendt, Instituut voor Kern- en Stralingsfysica, Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Grand Accélérateur National d'Ions Lourds (GANIL), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de physique corpusculaire de Caen (LPCC), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Physics [Jyväskylä Univ] (JYU), University of Jyväskylä (JYU), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Université de Haute-Alsace (UHA) Mulhouse - Colmar (Université de Haute-Alsace (UHA))-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut für Physik [Mainz], and Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU)
Subjects: Nuclear and High Energy Physics, resonance ionization laser spectroscopy, gas cell, hypersonic gas jets, radio frequency quadrupoles, nuclear ground state properties, isotope shift, hyperfine structure, spektroskopia, tutkimuslaitteet, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], Physics, Atomic, Molecular & Chemical, atomifysiikka, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Science & Technology, SPECTROSCOPY, [PHYS.PHYS.PHYS-ATOM-PH]Physics [physics]/Physics [physics]/Atomic Physics [physics.atom-ph], Physics, LASER ION-SOURCE, Condensed Matter Physics, lasertekniikka, Atomic and Molecular Physics, and Optics, Physical Sciences, IONIZATION, ydinfysiikka, SYSTEM
Abstract: International audience; We present the first results obtained from the S3 Low-Energy Branch , the gas cell setup at SPIRAL2-GANIL, which will be installed behind the S3 spectrometer for atomic and nuclear spectroscopy studies of exotic nuclei. The installation is currently being commissioned offline, with the aim to establish optimum conditions for the operation of the radio frequency quadrupole ion guides, mass separation and ion bunching, providing high-efficiency and low-energy spatial spread for the isotopes of interest. Transmission and mass-resolving power measurements are presented for the different components of the S3-LEB setup. In addition, a single-longitudinal-mode, injection-locked, pumped pulsed-titanium–sapphire laser system has been recently implemented and is used for the first proof-of-principle measurements in an offline laser laboratory. Laser spectroscopy measurements of erbium, which is the commissioning case of the S3 spectrometer, are presented using the 4f126s23H6→4f12(3H)6s6p optical transition.
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44. Effect of simple shear on knotted polymer coils and globules.

Author: Milchev A, Schmitt MP, and Virnau P
Abstract: We explore the effect of Couette flow on knotted linear polymer chains with extensive molecular dynamics simulations. Hydrodynamic interactions are accounted for using multi-particle collision dynamics. The polymer chain, originally containing a simple trefoil knot at rest, is described by a coarse-grained bead-spring model in a coil or globular state. We demonstrate that under shear existing loosely localized knots in polymer coils typically tighten to several segments beyond a certain shear rate threshold. At large shear rates, the polymer undergoes a tumbling-like motion during which knot sizes can fluctuate. In contrast, sheared knotted globules unwind into a convoluted pearl-necklace structure of sub-globules that folds back onto itself and in which knot types change over time., (© 2024 Author(s). Published under an exclusive license by AIP Publishing.)
Published: 2024
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45. 229 ThF 4 thin films for solid-state nuclear clocks.

Author: Zhang C, von der Wense L, Doyle JF, Higgins JS, Ooi T, Friebel HU, Ye J, Elwell R, Terhune JES, Morgan HWT, Alexandrova AN, Tran Tan HB, Derevianko A, and Hudson ER
Abstract: After nearly 50 years of searching, the vacuum ultraviolet 229 Th nuclear isomeric transition has recently been directly laser excited 1,2 and measured with high spectroscopic precision 3 . Nuclear clocks based on this transition are expected to be more robust 4,5 than and may outperform 6,7 current optical atomic clocks. These clocks also promise sensitive tests for new physics beyond the standard model 5,8-12 . In light of these important advances and applications, a substantial increase in the need for 229 Th spectroscopy targets in several platforms is anticipated. However, the growth and handling of high-concentration 229 Th-doped crystals 5 used in previous measurements 1-3,13,14 are challenging because of the scarcity and radioactivity of the 229 Th material. Here we demonstrate a potentially scalable solution to these problems by performing laser excitation of the nuclear transition in 229 ThF 4 thin films grown using a physical vapour deposition process, consuming only micrograms of 229 Th material. The 229 ThF 4 thin films are intrinsically compatible with photonics platforms and nanofabrication tools for integration with laser sources and detectors, paving the way for an integrated and field-deployable solid-state nuclear clock with radioactivity up to three orders of magnitude smaller than typical 229 Th-doped crystals 1-3,13 . The high nuclear emitter density in 229 ThF 4 also potentially enables quantum optics studies in a new regime. Finally, we present the estimation of the performance of a nuclear clock based on a defect-free ThF 4 crystal., Competing Interests: Competing interests: The authors declare no competing interests., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
Published: 2024
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46. Frequency ratio of the 229m Th nuclear isomeric transition and the 87 Sr atomic clock.

Author: Zhang C, Ooi T, Higgins JS, Doyle JF, von der Wense L, Beeks K, Leitner A, Kazakov GA, Li P, Thirolf PG, Schumm T, and Ye J
Abstract: Optical atomic clocks 1,2 use electronic energy levels to precisely keep track of time. A clock based on nuclear energy levels promises a next-generation platform for precision metrology and fundamental physics studies. Thorium-229 nuclei exhibit a uniquely low-energy nuclear transition within reach of state-of-the-art vacuum ultraviolet (VUV) laser light sources and have, therefore, been proposed for construction of a nuclear clock 3,4 . However, quantum-state-resolved spectroscopy of the 229m Th isomer to determine the underlying nuclear structure and establish a direct frequency connection with existing atomic clocks has yet to be performed. Here, we use a VUV frequency comb to directly excite the narrow 229 Th nuclear clock transition in a solid-state CaF 2 host material and determine the absolute transition frequency. We stabilize the fundamental frequency comb to the JILA 87 Sr clock 2 and coherently upconvert the fundamental to its seventh harmonic in the VUV range by using a femtosecond enhancement cavity. This VUV comb establishes a frequency link between nuclear and electronic energy levels and allows us to directly measure the frequency ratio of the 229 Th nuclear clock transition and the 87 Sr atomic clock. We also precisely measure the nuclear quadrupole splittings and extract intrinsic properties of the isomer. These results mark the start of nuclear-based solid-state optical clocks and demonstrate the first comparison, to our knowledge, of nuclear and atomic clocks for fundamental physics studies. This work represents a confluence of precision metrology, ultrafast strong-field physics, nuclear physics and fundamental physics., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)
Published: 2024
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47. Photoemission electron microscopy as a tool for the investigation of optical near fields.

Author: Cinchetti M, Gloskovskii A, Nepjiko SA, Schönhense G, Rochholz H, and Kreiter M
Abstract: Photoemission electron microscopy was used to image the electrons photoemitted from specially tailored Ag nanoparticles deposited on a Si substrate (with its native oxide SiO(x)). Photoemission was induced by illumination with a Hg UV lamp (photon energy cutoff homega(UV) = 5.0 eV, wavelength lambda(UV) = 250 nm) and with a Ti:sapphire femtosecond laser (homega(l) = 3.1 eV, lambda(l) = 400 nm, pulse width below 200 fs), respectively. While homogeneous photoelectron emission from the metal is observed upon illumination at energies above the silver plasmon frequency, at lower photon energies the emission is localized at tips of the structure. This is interpreted as a signature of the local electrical field therefore providing a tool to map the optical near field with the resolution of emission electron microscopy.
Published: 2005
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