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11 results on '"Institute of Physics [Graz]"'

1. Investigating Mercury's Environment with the Two-Spacecraft BepiColombo Mission

Author

Oleg Korablev, M. Fujimoto, Léa Griton, Cesare Grava, Masafumi Hirahara, Hirotsugu Kojima, S. Barabash, Wolfgang Baumjohann, A. Martindale, Chuanfei Dong, François Leblanc, Chris Carr, S. T. Lindsay, Yasumasa Kasaba, M. Kobayashi, Herbert Lichtenegger, Philippe-A. Bourdin, Karri Muinonen, J. S. Oliveira, Jan-Erik Wahlund, Ferdinand Plaschke, Christina Plainaki, S. M. P. McKenna-Lawlor, Dominique Delcourt, Eric Quémerais, Xianzhe Jia, Dusan Odstrcil, James A. Slavin, V. Mangano, M. G. Pelizzo, Benoit Langlais, Joe Zender, Emma J. Bunce, Ichiro Yoshikawa, Peter Wurz, Stavro Ivanovski, Stefano Massetti, George C. Ho, Y. Saito, Juhani Huovelin, Suzanne M. Imber, Sae Aizawa, Alessandro Mura, Jim M. Raines, Ayako Matsuoka, F. Sahraoui, Karl-Heinz Glassmeier, Pierre Henri, Rami Vainio, Matthew K. James, Rosemary M. Killen, Stefano Orsini, Shahab Fatemi, Tomas Karlsson, Monica Laurenza, Esa Kallio, Christoph Lhotka, Michiko Morooka, Johannes Benkhoff, David A. Rothery, Yasuhito Narita, Michel Moncuquet, Anna Milillo, Alexey A. Berezhnoy, Satoshi Yagitani, Adam Masters, F. Califano, Manuel Grande, Stefano Livi, Daniel Heyner, Emilia Kilpua, G. Murakami, Jan Deca, S. de la Fuente, R. Moissl, Bernard V. Jackson, Kanako Seki, N. André, M. Dósa, Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Wigner Research Centre for Physics [Budapest], Hungarian Academy of Sciences (MTA), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Space Research Centre [Leicester], University of Leicester, Department of Space and Plasma Physics [Stockholm], KTH School of Electrical Engineering, Royal Institute of Technology [Stockholm] (KTH )-Royal Institute of Technology [Stockholm] (KTH ), NASA Goddard Space Flight Center (GSFC), Space Technology Ireland Limited, Department of Climate and Space Sciences and Engineering (CLaSP), School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Sternberg Astronomical Institute [Moscow], Lomonosov Moscow State University (MSU), University of Pisa - Università di Pisa, University of Colorado [Boulder], European Space Astronomy Centre (ESAC), Princeton Plasma Physics Laboratory (PPPL), Princeton University, Department of Astrophysical Sciences [Princeton], Southwest Research Institute [San Antonio] (SwRI), Swedish Institute of Space Physics [Kiruna] (IRF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), INAF - Osservatorio Astronomico di Trieste (OAT), University of California [San Diego] (UC San Diego), University of California (UC), Department of Electronics and Nanoengineering [Espoo], School of Electrical Engineering [Aalto Univ], Aalto University-Aalto University, Planetary Plasma and Atmospheric Research Center [Sendai] (PPARC), Tohoku University [Sendai], Department of Physics [Helsinki], Falculty of Science [Helsinki], Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Planetary Exploration Research Center [Chiba] (PERC), Chiba Institute of Technology (CIT), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Blackett Laboratory, Imperial College London, Swedish Institute of Space Physics [Uppsala] (IRF), Institute of Physics [Graz], Karl-Franzens-Universität Graz, Centro de Investigação da Terra e do Espaço da UC (CITEUC), Universidade de Coimbra [Coimbra], CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Italian Space Agency, Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Planetary Science [Tokyo], Graduate School of Science [Tokyo], The University of Tokyo (UTokyo)-The University of Tokyo (UTokyo), Space Research Laboratory [Turku] (SRL), Department of Physics and Astronomy [Turku], University of Turku-University of Turku, Physics Institute [Bern], University of Bern, Department of Physics [Imperial College London], Institute of Mathematical and Physical Sciences [Aberystwyth], University of Wales, Institute for Space-Earth Environmental Research [Nagoya] (ISEE), Nagoya University, Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Graduate School of the Natural Science and Technology [Kanazawa], Kanazawa University (KU), Department of Complexity Science and Engineering [Tokyo], The University of Tokyo (UTokyo), European Space Agency (ESA), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), University of California, University of Helsinki-University of Helsinki, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Karl-Franzens-Universität [Graz, Autriche], Consiglio Nazionale delle Ricerche [Roma] (CNR), Kyoto University [Kyoto], Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), The Royal Society, Science and Technology Facilities Council, INAF National Institute for Astrophysics, JAXA Institute of Space and Astronautical Science, European Space Research and Technology Centre, IRAP, Hungarian Academy of Sciences, Technical University of Braunschweig, Johns Hopkins Applied Physics Laboratory, University of Michigan, Ann Arbor, KTH Royal Institute of Technology, NASA Goddard Space Flight Center, Space Technology Ireland, Open University Milton Keynes, Austrian Academy of Sciences, Lomonosov Moscow State University, University of Pisa, University of Colorado Boulder, European Space Astronomy Centre, Princeton Plasma Physics Laboratory, Southwest Research Institute, Uppsala University, Université d'Orléans, Osservatorio Astronomico di Trieste, University of California San Diego, Department of Electronics and Nanoengineering, Tohoku University, University of Helsinki, Chiba Institute of Technology, Université de Nantes, Sorbonne Université, University of Graz, National Research Council of Italy, Agenzia Spaziale Italiana, The University of Tokyo, University of Turku, Aberystwyth University, Space Research Institute of the Russian Academy of Sciences, Université de Versailles Saint-Quentin-en-Yvelines, Kanazawa University, Aalto-yliopisto, and Aalto University

Subjects
010504 meteorology & atmospheric sciences, Computer science, BepiColombo, chemistry.chemical_element, FOS: Physical sciences, Astronomy & Astrophysics, 01 natural sciences, Mercury’s environment, Fusion, plasma och rymdfysik, Interplanetary dust cloud, Astronomi, astrofysik och kosmologi, 0201 Astronomical and Space Sciences, 0103 physical sciences, Astronomy, Astrophysics and Cosmology, Exosphere, Magnetosphere, Aerospace engineering, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 0105 earth and related environmental sciences, Scientific instrument, Earth and Planetary Astrophysics (astro-ph.EP), Spacecraft, business.industry, 520 Astronomy, Astronomy and Astrophysics, 620 Engineering, Fusion, Plasma and Space Physics, Mercury (element), Solar wind, Planetary science, chemistry, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Mercury's environment, Mercury’s environment · Magnetosphere · Exosphere · BepiColombo, Astrophysics - Instrumentation and Methods for Astrophysics, business, Astrophysics - Earth and Planetary Astrophysics
Abstract

The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well as their interactions with the solar wind, radiation, and interplanetary dust. Many scientific instruments onboard the two spacecraft will be completely, or partially devoted to study the near-space environment of Mercury as well as the complex processes that govern it. Many issues remain unsolved even after the MESSENGER mission that ended in 2015. The specific orbits of the two spacecraft, MPO and Mio, and the comprehensive scientific payload allow a wider range of scientific questions to be addressed than those that could be achieved by the individual instruments acting alone, or by previous missions. These joint observations are of key importance because many phenomena in Mercury's environment are highly temporally and spatially variable. Examples of possible coordinated observations are described in this article, analysing the required geometrical conditions, pointing, resolutions and operation timing of different BepiColombo instruments sensors., Comment: 78 pages, 14 figures, published

Published
2022
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2. STIX X-ray microflare observations during the Solar Orbiter commissioning phase

Author

Andrea Francesco Battaglia, Jonas Saqri, Paolo Massa, Emma Perracchione, Ewan C. M. Dickson, Hualin Xiao, Astrid M. Veronig, Alexander Warmuth, Marina Battaglia, Gordon J. Hurford, Aline Meuris, Olivier Limousin, László Etesi, Shane A. Maloney, Richard A. Schwartz, Matej Kuhar, Frederic Schuller, Valliappan Senthamizh Pavai, Sophie Musset, Daniel F. Ryan, Lucia Kleint, Michele Piana, Anna Maria Massone, Federico Benvenuto, Janusz Sylwester, Michalina Litwicka, Marek Stȩślicki, Tomasz Mrozek, Nicole Vilmer, František Fárník, Jana Kašparová, Gottfried Mann, Peter T. Gallagher, Brian R. Dennis, André Csillaghy, Arnold O. Benz, Säm Krucker, University of Applied Sciences and Arts of Western Switzerland (HES-SO), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Institute of Physics [Graz], Karl-Franzens-Universität Graz, Dipartimento di Matematica [Genova], Università degli studi di Genova = University of Genoa (UniGe), Leibniz-Institut für Astrophysik Potsdam (AIP), Univ Paris Diderot, CEA, CNRS, Lab AIM, Gif Sur Yvette, France, Trinity College Dublin, Dublin Institute for Advanced Studies (DIAS), American University Washington D.C. (AU), NASA Goddard Space Flight Center (GSFC), SUPA School of Physics and Astronomy [Glasgow], University of Glasgow, Centre Universitaire d'Informatique (CUI), Université de Genève = University of Geneva (UNIGE), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Astronomical Institute [Wroclaw], University of Wrocław [Poland] (UWr), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Astronomical Institute of the Czech Academy of Sciences (ASU / CAS), Czech Academy of Sciences [Prague] (CAS), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley] (UC Berkeley), and University of California (UC)-University of California (UC)

Subjects
Sun: flares, Astrophysics::High Energy Astrophysical Phenomena, Phase (waves), FOS: Physical sciences, Astrophysics, 7. Clean energy, 01 natural sciences, law.invention, Orbiter, law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Gamma rays, Sun: corona, Sun: X-rays, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Physics, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 010308 nuclear & particles physics, X-ray, Astronomy and Astrophysics, gamma rays, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics
Abstract

The Spectrometer/Telescope for Imaging X-rays (STIX) is the HXR instrument onboard Solar Orbiter designed to observe solar flares over a broad range of flare sizes, between 4-150 keV. We report the first STIX observations of microflares recorded during the instrument commissioning phase in order to investigate the STIX performance at its detection limit. This first result paper focuses on the temporal and spectral evolution of STIX microflares occuring in the AR12765 in June 2020, and compares the STIX measurements with GOES/XRS, SDO/AIA, and Hinode/XRT. For the observed microflares of the GOES A and B class, the STIX peak time at lowest energies is located in the impulsive phase of the flares, well before the GOES peak time. Such a behavior can either be explained by the higher sensitivity of STIX to higher temperatures compared to GOES, or due to the existence of a nonthermal component reaching down to low energies. The interpretation is inconclusive due to limited counting statistics for all but the largest flare in our sample. For this largest flare, the low-energy peak time is clearly due to thermal emission, and the nonthermal component seen at higher energies occurs even earlier. This suggests that the classic thermal explanation might also be favored for the majority of the smaller flares. In combination with EUV and SXR observations, STIX corroborates earlier findings that an isothermal assumption is of limited validity. Future diagnostic efforts should focus on multi-wavelength studies to derive differential emission measure distributions over a wide range of temperatures to accurately describe the energetics of solar flares. Commissioning observations confirm that STIX is working as designed. As a rule of thumb, STIX detects flares as small as the GOES A class. For flares above the GOES B class, detailed spectral and imaging analyses can be performed., Comment: 19 pages, 11 figures

Published
2021
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3. Dust of comet 67P/Churyumov-Gerasimenko collected by Rosetta/MIDAS: classification and extension to the nanometer scale

Author

Thurid Mannel, Mark Bentley, Pascale Ehrenfreund, Klaus Torkar, J. Romstedt, Peter Boakes, Iris Weber, Cécile Engrand, H. Jeszenszky, Christian Koeberl, Roland Schmied, Anny Chantal Levasseur-Regourd, Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Institute of Physics [Graz], University of Graz, European Space Astronomy Centre (ESAC), European Space Agency (ESA), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Space Policy Institute [Washington], The George Washington University (GW), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Department of Lithospheric Research [Wien], Universität Wien, Natural History Museum [Vienna] (NHM), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), European Space Research and Technology Centre (ESTEC), Institut für Weltraumforschung [Graz] (IWF), Osterreichische Akademie der Wissenschaften (ÖAW), Institut für Planetologie [Münster], Westfälische Wilhelms-Universität Münster (WWU), Karl-Franzens-Universität [Graz, Autriche], and Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11)

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Physics, Planetesimal, Range (particle radiation), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010504 meteorology & atmospheric sciences, Comet, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, 01 natural sciences, Fractal dimension, Interplanetary dust cloud, 13. Climate action, Space and Planetary Science, Agglomerate, 0103 physical sciences, Particle, 010303 astronomy & astrophysics, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract

Context. The properties of the smallest subunits of cometary dust contain information on their origin and clues to the formation of planetesimals and planets. Compared to interplanetary dust particles or particles collected during the Stardust mission, dust collected in the coma of comet 67P/Churyumov-Gerasimenko (67P) during the Rosetta mission provides a resource of minimally altered material with known origin whose structural properties can be used to further the investigation of the early solar system. Aims. The cometary dust particle morphologies found at comet 67P on the micrometer scale are classified, and their structural analysis is extended to the nanometer scale. Methods. We present a novel method for achieving the highest spatial resolution of imaging obtained with the MIDAS Atomic Force Microscope on board Rosetta. 3D topographic images with resolutions down to 8 nm were analyzed to determine the subunit sizes of particles on the nanometer scale. Results. Three morphological classes can be determined: (i) fragile agglomerate particles of sizes larger than about 10 μm comprised of micrometer-sized subunits that may themselves be aggregates and show a moderate packing density on the surface of the particles. (ii) A fragile agglomerate with a size of about a few tens of micrometers comprised of micrometer-sized subunits that are suggested to be aggregates themselves and are arranged in a structure with a fractal dimension lower than two. (iii) Small micrometer-sized particles comprised of subunits in the size range of hundreds of nanometers that show surface features that are again suggested to represent subunits. Their differential size distributions follow a log-normal distribution with means of about 100 nm and standard deviations between 20 and 35 nm. Conclusions. The properties of the dust particles found by MIDAS represent an extension of the dust results of Rosetta to the micro- and nanometer scale. All micrometer-sized particles are hierarchical dust agglomerates of smaller subunits. The arrangement, appearance, and size distribution of the smallest determined surface features are reminiscent of those found in chondritic porous interplanetary dust particles. They represent the smallest directly detected subunits of comet 67P.

Published
2019
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4. Coulomb correlations in 4d and 5d oxides from first principles—or how spin–orbit materials choose their effective orbital degeneracies

Author

Martins, Cyril, Aichhorn, Markus, Biermann, Silke, Systèmes étendus et magnétisme (LCPQ) (SEM), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), 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)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Department of Theoretical Physics [Graz], Institute of Physics [Graz], Karl-Franzens-Universität [Graz, Autriche]-Karl-Franzens-Universität [Graz, Autriche], Centre de Physique Théorique [Palaiseau] (CPHT), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)

Subjects
Condensed Matter - Strongly Correlated Electrons, Strongly Correlated Electrons (cond-mat.str-el), FOS: Physical sciences, [PHYS.COND.CM-SCE]Physics [physics]/Condensed Matter [cond-mat]/Strongly Correlated Electrons [cond-mat.str-el], ComputingMilieux_MISCELLANEOUS
Abstract

The interplay of spin-orbit interactions and Coulomb correlations has become a hot topic in condensed matter theory. Here, we review recent advances in dynamical mean-field theory-based electronic structure calculations for iridates and rhodates. We stress the notion of the effective degeneracy of the compounds, which introduces an additional axis into the conventional picture of a phase diagram based on filling and on the ratio of interactions to bandwidth., 45 pages, 9 figures in \Psi_k Scientific Highlight Of The Month 132 (Novembre 2016)

Published
2017
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5. Aggregate dust particles at comet 67P/Churyumov–Gerasimenko

Author

H. Jeszenszky, Ove Havnes, Pascale Ehrenfreund, Christian Koeberl, Mark Bentley, Thurid Mannel, J. Romstedt, Roland Schmied, Iris Weber, Klaus Torkar, Elmar K. Jessberger, Anny Chantal Levasseur-Regourd, Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Institute of Physics [Graz], University of Graz, European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), PLANETO - 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), Universidade Federal de Pernambuco [Recife] (UFPE), Institut für Planetologie [Münster], Westfälische Wilhelms-Universität Münster (WWU), Space Policy Institute [Washington], The George Washington University (GW), Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Natural History Museum [Vienna] (NHM), Department of Lithospheric Research [Wien], Universität Wien, Tromsø Geophysical Observatory (TGO), The Arctic University of Norway (UiT), Department of Physics and Technology [Tromsø], University of Tromsø (UiT), Karl-Franzens-Universität [Graz, Autriche], Karl-Franzens-Universität Graz, Agence Spatiale Européenne = European Space Agency (ESA), Westfälische Wilhelms-Universität Münster = University of Münster (WWU), Universiteit Leiden, and The Arctic University of Norway [Tromsø, Norway] (UiT)

Subjects
010504 meteorology & atmospheric sciences, Comet dust, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Astrophysics, 01 natural sciences, Astrobiology, Kuiper belt, Interplanetary dust cloud, 0103 physical sciences, comets, Early solar system, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Cosmic dust, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Multidisciplinary, Asteroids, Particle aggregation, 13. Climate action, Asteroid, Agglomerate, Formation and evolution of the Solar System, Astrophysics - Earth and Planetary Astrophysics
Abstract

International audience; Comets are thought to preserve almost pristine dust particles, thus providing a unique sample of the properties of the early solar nebula. The microscopic properties of this dust played a key part in particle aggregation during the formation of the Solar System1, 2. Cometary dust was previously considered to comprise irregular, fluffy agglomerates on the basis of interpretations of remote observations in the visible and infrared3, 4, 5, 6 and the study of chondritic porous interplanetary dust particles7 that were thought, but not proved, to originate in comets. Although the dust returned by an earlier mission8 has provided detailed mineralogy of particles from comet 81P/Wild, the fine-grained aggregate component was strongly modified during collection9. Here we report in situ measurements of dust particles at comet 67P/Churyumov–Gerasimenko. The particles are aggregates of smaller, elongated grains, with structures at distinct sizes indicating hierarchical aggregation. Topographic images of selected dust particles with sizes of one micrometre to a few tens of micrometres show a variety of morphologies, including compact single grains and large porous aggregate particles, similar to chondritic porous interplanetary dust particles. The measured grain elongations are similar to the value inferred for interstellar dust and support the idea that such grains could represent a fraction of the building blocks of comets. In the subsequent growth phase, hierarchical agglomeration could be a dominant process10 and would produce aggregates that stick more easily at higher masses and velocities than homogeneous dust particles11. The presence of hierarchical dust aggregates in the near-surface of the nucleus of comet 67P also provides a mechanism for lowering the tensile strength of the dust layer and aiding dust release12.

Published
2016
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6. TRIQS/DFTTools: A TRIQS application for ab initio calculations of correlated materials

Author

Jernej Mravlje, Markus Aichhorn, Leonid Pourovskii, Verónica Vildosola, Olivier Parcollet, Xiaoyu Deng, Manuel Zingl, Gernot J. Kraberger, Priyanka Seth, Oleg E. Peil, Michel Ferrero, Cyril Martins, Department of Theoretical Physics [Graz], Institute of Physics [Graz], Karl-Franzens-Universität Graz-Karl-Franzens-Universität Graz, Centre de Physique Théorique [Palaiseau] (CPHT), École polytechnique (X)-Centre National de la Recherche Scientifique (CNRS), Collège de France - Chaire Physique de la matière condensée (A. Georges), Collège de France (CdF (institution)), Institut de Physique Théorique - UMR CNRS 3681 (IPHT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Genève = University of Geneva (UNIGE), Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers), Jozef Stefan Institute [Ljubljana] (IJS), Systèmes étendus et magnétisme (LCPQ) (SEM), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), European Project: 617196,EC:FP7:ERC,ERC-2013-CoG,CORRELMAT(2014), European Project: 278472,EC:FP7:ERC,ERC-2011-StG_20101014,MOTTMETALS(2012), Karl-Franzens-Universität [Graz, Autriche]-Karl-Franzens-Universität [Graz, Autriche], Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Chaire Physique de la matière condensée (A. Georges), University of Geneva [Switzerland], Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse)

Subjects
ab-initio calculations, Computer science, Interface (Java), Ciencias Físicas, Ab initio, General Physics and Astronomy, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Computational science, WIEN2k, Condensed Matter - Strongly Correlated Electrons, Ab initio quantum chemistry methods, 0103 physical sciences, 010306 general physics, Electronic band structure, Strongly-correlated electrons, Basis set, [PHYS]Physics [physics], Wannier function, Condensed Matter - Materials Science, Strongly Correlated Electrons (cond-mat.str-el), Materials Science (cond-mat.mtrl-sci), 021001 nanoscience & nanotechnology, Computational physics, Dynamical mean-field theory, Many-body physics, Hardware and Architecture, Density functional theory, 0210 nano-technology, CIENCIAS NATURALES Y EXACTAS, Física de los Materiales Condensados
Abstract

We present the TRIQS/DFTTools package, an application based on the TRIQS library that connects this toolbox to realistic materials calculations based on density functional theory (DFT). In particular, TRIQS/DFTTools together with TRIQS allows an efficient implementation of DFT plus dynamical mean-field theory (DMFT) calculations. It supplies tools and methods to construct Wannier functions and to perform the DMFT self-consistency cycle in this basis set. Post-processing tools, such as band-structure plotting or the calculation of transport properties are also implemented. The package comes with a fully charge self-consistent interface to the Wien2k band structure code, as well as a generic interface that allows to use TRIQS/DFTTools together with a large variety of DFT codes. It is distributed under the GNU General Public License (GPLv3)., Comment: 18 pages, 6 figures, Comp. Phys. Comm. accepted version

Published
2016
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7. The PAC2MAN mission: a new tool to understand and predict solar energetic events

Author

Sophie Musset, Jorge Amaya, René Kiefer, Solène Lejosne, Mirko Rummelhagen, Andrea Diercke, Christian Höller, Riccardo Lasagni, S. Thonhofer, Viktor Andersson, Lilla Juhász, Mohammad Madi, Sergiu Iliev, Markus Scheucher, Arianna Sorba, Centre for Mathematical Plasma-Astrophysics [Leuven] (CmPA), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Kiruna] (IRF), Leibniz-Institut für Astrophysik Potsdam (AIP), Institut für Physik und Astrophysik [Potsdam], University of Potsdam = Universität Potsdam, Faculty of Mechanical and Industrial Engineering, Department for Space Mechanisms, Aeronautical Engineering Department, Imperial College London, Department of Geophysics and Space Research [Budapest], Eötvös Loránd University (ELTE), Kiepenheuer-Institut für Sonnenphysik (KIS), Department of Aerospace Engineering, British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Micos Engineering GmbH, Berner & Mattner Systemtechnik, Institute of Physics [Graz], Karl-Franzens-Universität Graz, Blackett Laboratory, Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Universität Potsdam, Karl-Franzens-Universität [Graz, Autriche], and Jorge Amaya, Sophie Musset, Viktor Andersson, Andrea Diercke, Christian Höller, Sergiu Iliev, Lilla Juhász, René Kiefer, Riccardo Lasagni, Solène Lejosne, Mohammad Madi, Mirko Rummelhagen, Markus Scheucher, Arianna Sorba, Stefan Thonhofer

Subjects
Atmospheric Science, Space weather, FOS: Physical sciences, Mission, lcsh:QC851-999, 7. Clean energy, Missions, Coronal mass ejection (CME), Coronal mass ejection, Astrophysics::Solar and Stellar Astrophysics, Spacecraft, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), Physics::Atmospheric and Oceanic Physics, Remote sensing, Physics, Solar conjunction, business.industry, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Coronal loop, Solar wind, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, lcsh:Meteorology. Climatology, Astrophysics::Earth and Planetary Astrophysics, business, Astrophysics - Instrumentation and Methods for Astrophysics, Heliocentric orbit, Flare, Space environment
Abstract

An accurate forecast of flare and CME initiation requires precise measurements of the magnetic energy build up and release in the active regions of the solar atmosphere. We designed a new space weather mission that performs such measurements using new optical instruments based on the Hanle and Zeeman effects. The mission consists of two satellites, one orbiting the L1 Lagrangian point (Spacecraft Earth, SCE) and the second in heliocentric orbit at 1AU trailing the Earth by 80$^\circ$ (Spacecraft 80, SC80). Optical instruments measure the vector magnetic field in multiple layers of the solar atmosphere. The orbits of the spacecraft allow for a continuous imaging of nearly 73\% of the total solar surface. In-situ plasma instruments detect solar wind conditions at 1AU and ahead of our planet. Earth directed CMEs can be tracked using the stereoscopic view of the spacecraft and the strategic placement of the SC80 satellite. Forecasting of geoeffective space weather events is possible thanks to an accurate surveillance of the magnetic energy build up in the Sun, an optical tracking through the interplanetary space, and in-situ measurements of the near-Earth environment., Accepted for publication in the Journal of Space Weather and Space Climate (SWSC)

Published
2014
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8. Solar Energetic Particles and Associated EIT Disturbances in Solar Cycle 23

Author

I. W. Kienreich, Olga Malandraki, Karl-Ludwig Klein, Astrid Veronig, Rositsa Miteva, Manuela Temmer, Space Research and Technology Institute [Sofia], Bulgarian Academy of Sciences (BAS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics [Graz], Karl-Franzens-Universität Graz, Demokritos University of Thrace, Department of Electrical Engineering, Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Karl-Franzens-Universität [Graz, Autriche]

Subjects
Physics, [PHYS]Physics [physics], Solar energetic particles, Proton, FOS: Physical sciences, Solar cycle 23, Astronomy and Astrophysics, Astrophysics, Electron, Corona, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Coronal mass ejection, Extreme ultraviolet Imaging Telescope, Astrophysics::Solar and Stellar Astrophysics, Heliospheric current sheet, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS
Abstract

We explore the link between solar energetic particles (SEPs) observed at 1 AU and large-scale disturbances propagating in the solar corona, named after the Extreme ultraviolet Imaging Telescope (EIT) as EIT waves, which trace the lateral expansion of a coronal mass ejection (CME). A comprehensive search for SOHO/EIT waves was carried out for 179 SEP events during Solar Cycle 23 (1997 – 2006). 87 % of the SEP events were found to be accompanied by EIT waves. In order to test if the EIT waves play a role in the SEP acceleration, we compared their extrapolated arrival time at the footpoint of the Parker spiral with the particle onset in the 26 eastern SEP events that had no direct magnetic connection to the Earth. We find that the onset of proton events was generally consistent with this scenario. However, in a number of cases the first near-relativistic electrons were detected too early. Furthermore, the electrons had in general only weakly anisotropic pitch-angle distributions. This poses a problem for the idea that the SEPs were accelerated by the EIT wave or in any other spatially confined region in the low corona. The presence of weak electron anisotropies in SEP events from the eastern hemisphere suggests that transport processes in interplanetary space, including cross-field diffusion, play a role in giving the SEPs access to a broad range of helio-longitudes.

Published
2014
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9. Initiation of Coronal Mass Ejections by Sunspot Rotation

Author

Tibor Torok, Astrid Veronig, Manuela Temmer, Bojan Vršnak, Gherardo Valori, Lidia van Driel-Gesztelyi, Institute of Physics [Graz], Karl-Franzens-Universität [Graz, Autriche], Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique solaire, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Karl-Franzens-Universität Graz, University of Graz, and PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)

Subjects
010504 meteorology & atmospheric sciences, Field (physics), Magnetic fields - corona, Active regions - models, Coronal mass ejections - initiation and propagation, Sunspots - velocity, FOS: Physical sciences, Astrophysics, Rotation, 01 natural sciences, law.invention, Protein filament, law, 0103 physical sciences, Coronal mass ejection, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Physics, [PHYS]Physics [physics], Sunspot, Astronomy and Astrophysics, Magnetic field, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Magnetohydrodynamics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Flare
Abstract

We study a filament eruption, two-ribbon flare, and coronal mass ejection (CME) that occurred in Active Region NOAA 10898 on 6 July 2006. The filament was located South of a strong sunspot that dominated the region. In the evolution leading up to the eruption, and for some time after it, a counter-clockwise rotation of the sunspot of about 30 degrees was observed. We suggest that the rotation triggered the eruption by progressively expanding the magnetic field above the filament. To test this scenario, we study the effect of twisting the initially potential field overlying a pre-existing flux-rope, using three-dimensional zero-$\beta$ MHD simulations. We first consider a relatively simple and symmetric system, and then study a more complex and asymmetric magnetic configuration, whose photospheric flux distribution and coronal structure are guided by the observations and a potential field extrapolation. In both cases, we find that the twisting leads to the expansion of the overlying field. As a consequence of the progressively reduced magnetic tension, the flux-rope quasi-statically adapts to the changed environmental field, rising slowly. Once the tension is sufficiently reduced, a distinct second phase of evolution occurs where the flux-rope enters an unstable regime characterized by a strong acceleration. Our simulations thus suggest a new mechanism for the triggering of eruptions in the vicinity of rotating sunspots., Comment: 28 pages, 10 figures

Published
2013
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10. Hallmark of strong electronic correlations in LaNiO3: Photoemission kink and broadening of fully occupied bands

Author

Antoine Georges, Michel Ferrero, Markus Aichhorn, Xiaoyu Deng, Jernej Mravlje, Rutgers, The State University of New Jersey [New Brunswick] (RU), Rutgers University System (Rutgers), Centre National de la Recherche Scientifique (CNRS), Centre de Physique Théorique [Palaiseau] (CPHT), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Chaire Physique de la matière condensée (A. Georges), Collège de France (CdF (institution)), Jozef Stefan Institute [Ljubljana] (IJS), Department of Theoretical Physics [Graz], Institute of Physics [Graz], Karl-Franzens-Universität [Graz, Autriche]-Karl-Franzens-Universität [Graz, Autriche], Laboratoire de Physique de la Matière Condensée (LPMC), and Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], Physics, Strongly Correlated Electrons (cond-mat.str-el), biology, Condensed matter physics, FOS: Physical sciences, Angle-resolved photoemission spectroscopy, Fermi energy, Condensed Matter Physics, biology.organism_classification, 01 natural sciences, 010305 fluids & plasmas, Electronic, Optical and Magnetic Materials, Renormalization, Condensed Matter - Strongly Correlated Electrons, Dynamical mean field theory, 0103 physical sciences, Dispersion (optics), Quasiparticle, Lanio, Condensed Matter::Strongly Correlated Electrons, Strongly correlated material, Atomic physics, 010306 general physics, ComputingMilieux_MISCELLANEOUS
Abstract

Recent angular-resolved photoemission experiments on LaNiO$_3$ reported a renormalization of the Fermi velocity of $e_g$ quasiparticles, a kink in their dispersion at $ -0.2$ eV and a large broadening and weakened dispersion of the occupied $t_{2g}$ states. We show here that all these features result from electronic correlations and are quantitatively reproduced by calculations combining density-functional theory and dynamical mean-field theory. The importance and general relevance of correlation effects in filled bands coupled by inter-orbital interactions to a partially-filled band are pointed out., Comment: 5 pages, 5 figures

Published
2012
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11. Dynamical mean-field theory within an augmented plane-wave framework: Assessing electronic correlations in the iron pnictide LaFeAsO

Author

Markus Aichhorn, Silke Biermann, Olivier Parcollet, Michel Ferrero, Leonid Pourovskii, Antoine Georges, Verónica Vildosola, Takashi Miyake, Department of Theoretical Physics [Graz], Institute of Physics [Graz], Karl-Franzens-Universität [Graz, Autriche]-Karl-Franzens-Universität [Graz, Autriche], Centre de Physique Théorique [Palaiseau] (CPHT), Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Centre National de la Recherche Scientifique (CNRS), Institut de Physique Théorique - UMR CNRS 3681 (IPHT), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Nanosystem Research Institute (NRI) RICS, AIST, Nanosystem Research Institute, Chaire Physique de la matière condensée (A. Georges), Collège de France (CdF (institution)), Laboratoire de Physique de la Matière Condensée (LPMC), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Japan Science and Technology Agency (JST), Karl-Franzens-Universität Graz-Karl-Franzens-Universität Graz, École polytechnique (X)-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), and Collège de France - Chaire Physique de la matière condensée (A. Georges)

Subjects
Quantum Monte Carlo, Plane wave, FOS: Physical sciences, 02 engineering and technology, 01 natural sciences, Renormalization, Superconductivity (cond-mat.supr-con), Condensed Matter - Strongly Correlated Electrons, Atomic orbital, Quantum mechanics, 0103 physical sciences, Sensitivity (control systems), 010306 general physics, ComputingMilieux_MISCELLANEOUS, Physics, [PHYS]Physics [physics], Wannier function, Degree (graph theory), Strongly Correlated Electrons (cond-mat.str-el), Condensed Matter - Superconductivity, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Coupling (probability), Electronic, Optical and Magnetic Materials, Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology
Abstract

We present an approach that combines the local density approximation (LDA) and the dynamical mean-field theory (DMFT) in the framework of the full-potential linear augmented plane waves (FLAPW) method. Wannier-like functions for the correlated shell are constructed by projecting local orbitals onto a set of Bloch eigenstates located within a certain energy window. The screened Coulomb interaction and Hund's coupling are calculated from a first-principle constrained RPA scheme. We apply this LDA+DMFT implementation, in conjunction with continuous-time quantum Monte-Carlo, to study the electronic correlations in LaFeAsO. Our findings support the physical picture of a metal with intermediate correlations. The average value of the mass renormalization of the Fe 3d bands is about 1.6, in reasonable agreement with the picture inferred from photoemission experiments. The discrepancies between different LDA+DMFT calculations (all technically correct) which have been reported in the literature are shown to have two causes: i) the specific value of the interaction parameters used in these calculations and ii) the degree of localization of the Wannier orbitals chosen to represent the Fe 3d states, to which many-body terms are applied. The latter is a fundamental issue in the application of many-body calculations, such as DMFT, in a realistic setting. We provide strong evidence that the DMFT approximation is more accurate and more straightforward to implement when well-localized orbitals are constructed from a large energy window encompassing Fe-3d, As-4p and O-2p, and point out several difficulties associated with the use of extended Wannier functions associated with the low-energy iron bands. Some of these issues have important physical consequences, regarding in particular the sensitivity to the Hund's coupling., Comment: 16 pages, 9 figures, published version

Published
2009
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