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1. Interplay of structure and photophysics of individualized rod-shaped graphene quantum dots with up to 132 sp² carbon atoms

Author

Daniel Medina-Lopez, Thomas Liu, Silvio Osella, Hugo Levy-Falk, Nicolas Rolland, Christine Elias, Gaspard Huber, Pranav Ticku, Loïc Rondin, Bruno Jousselme, David Beljonne, Jean-Sébastien Lauret, and Stephane Campidelli

Subjects
Science
Abstract

Abstract Nanographene materials are promising building blocks for the growing field of low-dimensional materials for optics, electronics and biophotonics applications. In particular, bottom-up synthesized 0D graphene quantum dots show great potential as single quantum emitters. To fully exploit their exciting properties, the graphene quantum dots must be of high purity; the key parameter for efficient purification being the solubility of the starting materials. Here, we report the synthesis of a family of highly soluble and easily processable rod-shaped graphene quantum dots with fluorescence quantum yields up to 94%. This is uncommon for a red emission. The high solubility is directly related to the design of the structure, allowing for an accurate description of the photophysical properties of the graphene quantum dots both in solution and at the single molecule level. These photophysical properties were fully predicted by quantum-chemical calculations.

Published
2023
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2. Temporal Variation in Von Bertalanffy Growth Curves and Generation Time of Southern Gulf of St. Lawrence Spring and Fall Spawning Atlantic Herring (Clupea harengus)

Author

Jacob Burbank, Jenni L. McDermid, François Turcotte, and Nicolas Rolland

Subjects
Atlantic herring, life history, growth, generation time, stock assessment, Biology (General), QH301-705.5, Genetics, QH426-470
Abstract

Examining temporal changes in the growth and generation time of fish species can be valuable for understanding population responses to different management measures and environmental conditions. Atlantic herring (Clupea harengus-Linnaeus, 1758) is an ecologically and commercially important pelagic forage fish species that occupies the southern Gulf of St. Lawrence. Here, we developed von Bertalanffy growth curves and estimated yearly values of generation time for NAFO Division 4TVn Atlantic herring for the years from 1988 to 2021. The results indicate a temporal reduction in the growth and generation time of both spring and fall spawning herring. Over the time series, the generation time of spring and fall spawners reduced by approximately 1 and 2 years, respectively. Furthermore, the average generation time of spring spawners across the time series (6.23 years (95% CI: 5.78–6.85 years)) was approximately 1 year lower than that of fall spawners (7.52 years (6.82–8.34 years)). Overall, the findings of this study can be used to better inform stock assessments and rebuilding plans for 4TVn spring and fall spawning Atlantic herring and highlight the importance of examining temporal trends in growth and generation time for more effective management of fish stocks.

Published
2023
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3. The Palaeolithic colonization of Europe: an archaeological and biogeographic perspective

Author

Nicolas Rolland

Subjects
colonización europea durante el paleolítico inferior, “cultura de cantos trabajados”, achelense, “horizonte paleolítico inicial europeo”, bifaces/hendedores, homo erectus, biogeografía, los casos de dispersión faunística, carnívoros africanos, corredor de dispersión, camino filtro, el caso de la dispersión del villafranquiense final/galeriense, paleogeografía, corredor del levante, maghreb, puente terrestre ibero-marroquí, asia central, geocronología, pleistoceno inferior-medio, fase jaramillo, fase matuyama final, fase brunhes, Archaeology, CC1-960
Abstract

Sintetizamos el conocimiento actual sobre el poblamiento de Europa durante el Paleolítico inferior, empleando datos de repertorios líticos, así como evidencia geocronológica, biogeográfica y paleogeográfica. Los vestigios humanos más antiguos pertenecen a un horizonte no-Achelense con una edad entre 0.90 y 0.55 ma. Buscando el origen geográfico y los caminos de dispersión hasta Europa, identificamos tres alternativas: a través del corredor del Levante, del estrecho de Gibraltar O, más improbablemente, por un camino de tipo filtro desde Asia Central. No existen pruebas definitivas para ninguna de esas alternativas pero hay un apoyo empírico más coherente para la hipótesis de Asia Central, donde existe también un repertorio no-Achelense. Según esta alternativa, la colonización de Europa coincide con un importante cambio en la fauna pleistocénica, la dispersión del final del Villafranquiense/Galeriense, la cual también se originó en Asia Central.

Published
1992
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5. A global database of Holocene paleotemperature records

Author

Marcela Sandra Tonello, Vincent Montade, Walter Finsinger, Karen J. Taylor, Manuel Chevalier, Isabelle Larocque-Tobler, Philipp Sommer, Nicholas P. McKay, Mateusz Płóciennik, Snezhana Zhilich, David F. Porinchu, Andrei Andreev, Markus Heinrichs, Tomi P. Luoto, Elena A. Ilyashuk, Anson W. Mackay, Deborah Khider, Stephen J. Roberts, Cody C. Routson, Les C. Cwynar, Samuel L Jaccard, Naomi Holmes, Kira Rehfeld, Aaron P. Potito, Emma J. Pearson, Steve Juggins, Anais Orsi, Louise C. Foster, Angela Self, Sakari Salonen, Basil A. S. Davis, Boris K. Biskaborn, Christoph Dätwyler, Sebastien Bertrand, Anne de Vernal, Jeannine Marie St-Jacques, Angelica Feurdean, Janet M. Wilmshurst, Lukas Jonkers, Heikki Seppä, Stephen J. Brooks, Elizabeth K. Thomas, Sonja Hausmann, Peter G. Langdon, Steven B. Malevich, Larisa Nazarova, Shyhrete Shala, Enikö Magyari, Matthew Peros, Scott A. Reinemann, Krystyna M. Saunders, Elena Novenko, Barbara Stenni, Yarrow Axford, Liudmila Syrykh, Julien Emile-Geay, Nicolas Rolland, Bryan G. Mark, Jianyong Li, Andria Dawson, Mathew Fox, André F. Lotter, Jessica E. Tierney, Oliver Heiri, Stefan Engels, Ian R. Walker, Andrew P. Rees, Pol Tarrats, Valerie van den Bos, Konrad Gajewski, Brian M. Chase, Eugene R. Wahl, Martin Grosjean, Boris P. Ilyashuk, Thomas Brussel, Mónika Tóth, Enlou Zhang, Darrell S. Kaufman, Olivier Cartapanis, Magaly Caniupán, Julieta Massaferro, Reinhard Pienitz, John M. Fegyveresi, Manuel Bringué, Carrie Morrill, Gaute Velle, M. P. Erb, Marie Claude Fortin, Petr Pařil, Karin A. Koinig, Richard S. Vachula, Paola Moffa-Sanchez, Jeremiah Marsicek, Northern Arizona University [Flagstaff], Institute of Earth Surface Dynamics [Lausanne], Université de Lausanne (UNIL), Utrecht University Palaeoecology, Laboratory of Palaeobotany and Palynology (UTRECHT UNIVERSITY), Utrecht University [Utrecht], Oeschger Centre for Climate Change Research (OCCR), University of Bern, University of Arizona, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UR226, Mount Royal University, Centre de recherche sur la dynamique du système Terre (GEOTOP), Université de Montréal (UdeM)-McGill University = Université McGill [Montréal, Canada]-École Polytechnique de Montréal (EPM)-Concordia University [Montreal]-Université du Québec à Rimouski (UQAR)-Université du Québec à Montréal = University of Québec in Montréal (UQAM)-Université du Québec en Abitibi-Témiscamingue (UQAT), Center for Marine Environmental Sciences [Bremen] (MARUM), Universität Bremen, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institute of Environmental Physics [Heidelberg] (IUP), Universität Heidelberg [Heidelberg], Programme CIT, Ligue Nationale Contre le Cancer, Snecma Propulsion Solide (SPS), SAFRAN Group, University of Southern California (USC), Senckenberg biodiversität und klima forschungszentrum (BIK-F), Forschungsinstitut Senckenberg (SGN), Université d'Ottawa [Ontario] (uOttawa), Faculty of Biological and Environmental Sciences [Helsinki], University of Helsinki, Department of Environmental and Landscape Geography, Eötvös Loránd University (ELTE), MTA-MTM-ELTE Research Group for Paleontology, Eötvös Loránd University (ELTE)-Hungarian Academy of Sciences (MTA), GINOP Sustainable Ecosystem Research Group, MTA Centre for Ecological Research [Tihany], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET), Centre d'Etudes Nordiques (CEN), Université Laval [Québec] (ULaval), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Department of Geosciences and Geography [Helsinki], Falculty of Science [Helsinki], University of Helsinki-University of Helsinki, Departemanto di Scienze Ambientali Informatica e Statistica (DAIS), University of Ca’ Foscari [Venice, Italy], Uni Research Environment, Uni Research Ltd, University of Bath [Bath], Université de Lausanne = University of Lausanne (UNIL), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), École Polytechnique de Montréal (EPM)-McGill University = Université McGill [Montréal, Canada]-Université de Montréal (UdeM)-Université du Québec en Abitibi-Témiscamingue (UQAT)-Université du Québec à Rimouski (UQAR)-Concordia University [Montreal]-Université du Québec à Montréal = University of Québec in Montréal (UQAM), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Universität Heidelberg [Heidelberg] = Heidelberg University, Ligue Nationale Contre le Cancer (LNCC), Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Faculty of Biological and Environmental Sciences, and Department of Geosciences and Geography

Subjects
Peat, 010504 meteorology & atmospheric sciences, 580 Plants (Botany), computer.software_genre, 01 natural sciences, MILLENNIAL-SCALE CHANGES, Proxy (climate), purl.org/becyt/ford/1 [https], purl.org/becyt/ford/1.5 [https], INTERTROPICAL CONVERGENCE ZONE, HOLOCENE, 910 Geography & travel, lcsh:Science, Holocene, LAKE VUOLEP-NJAKAJAURE, geography.geographical_feature_category, Database, EASTERN TIBETAN PLATEAU, [SDV.BIBS]Life Sciences [q-bio]/Quantitative Methods [q-bio.QM], Computer Science Applications, LATE-QUATERNARY VEGETATION, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, SEA-SURFACE TEMPERATURE, PROXIES, Statistics, Probability and Uncertainty, geog, Geology, Information Systems, Statistics and Probability, 1171 Geosciences, 010506 paleontology, NORTHERN NORTH-ATLANTIC, DATABASE, PALEOTEMPERATURE, [SDE.MCG]Environmental Sciences/Global Changes, education, Library and Information Sciences, Education, Paleoclimatology, SOUTH CHINA SEA, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, Southern Hemisphere, 1172 Environmental sciences, POLLEN-BASED RECONSTRUCTION, 550 Earth sciences & geology, 0105 earth and related environmental sciences, geography, [INFO.INFO-DB]Computer Science [cs]/Databases [cs.DB], Intertropical Convergence Zone, Glacier, 15. Life on land, WESTERN EQUATORIAL PACIFIC, Sea surface temperature, 13. Climate action, Settore GEO/08 - Geochimica e Vulcanologia, Earth and Environmental Sciences, lcsh:Q, computer
Abstract

A comprehensive database of paleoclimate records is needed to place recent warming into the longer-term context of natural climate variability. We present a global compilation of quality-controlled, published, temperature-sensitive proxy records extending back 12,000 years through the Holocene. Data were compiled from 679 sites where time series cover at least 4000 years, are resolved at sub-millennial scale (median spacing of 400 years or finer) and have at least one age control point every 3000 years, with cut-off values slackened in data-sparse regions. The data derive from lake sediment (51%), marine sediment (31%), peat (11%), glacier ice (3%), and other natural archives. The database contains 1319 records, including 157 from the Southern Hemisphere. The multi-proxy database comprises paleotemperature time series based on ecological assemblages, as well as biophysical and geochemical indicators that reflect mean annual or seasonal temperatures, as encoded in the database. This database can be used to reconstruct the spatiotemporal evolution of Holocene temperature at global to regional scales, and is publicly available in Linked Paleo Data (LiPD) format. Fil: Kaufman, Darrell. Northern Arizona University.; Estados Unidos Fil: McKay, Nicholas. Northern Arizona University.; Estados Unidos Fil: Routson, Cody. Northern Arizona University.; Estados Unidos Fil: Erb, Michael. Northern Arizona University.; Estados Unidos Fil: Davis, Basil. University Of Lausanne; Suiza Fil: Heiri, Oliver. University Of Basel; Suiza Fil: Jaccard, Samuel. University Of Bern; Suiza Fil: Tierney, Jessica. University of Arizona; Estados Unidos Fil: Dätwyler, Christoph. University Of Bern; Suiza Fil: Axford, Yarrow. Northwestern University; Estados Unidos Fil: Brussel, Thomas. University of Utah; Estados Unidos Fil: Cartapanis, Olivier. University Of Bern; Suiza Fil: Chase, Brian. Universite de Montpellier; Francia Fil: Dawson, Andria. Mount Royal University; Canadá Fil: de Vernal, Anne. Université du Québec a Montreal; Canadá Fil: Engels, Stefan. University of London; Reino Unido Fil: Jonkers, Lukas. University Of Bremen; Alemania Fil: Marsicek, Jeremiah. University of Wisconsin-Madison; Estados Unidos Fil: Moffa Sánchez, Paola. University of Durham; Reino Unido Fil: Morrill, Carrie. University of Colorado; Estados Unidos Fil: Orsi, Anais. Université Paris-Saclay; Francia Fil: Rehfeld, Kira. Heidelberg University; Alemania Fil: Saunders, Krystyna. Australian Nuclear Science And Technology Organisation; Australia Fil: Sommer, Philipp. University Of Lausanne; Suiza Fil: Thomas, Elizabeth. University At Buffalo; Estados Unidos Fil: Tonello, Marcela Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Tóth, Mónika. Balaton Limnological Institute; Hungría Fil: Vachula, Richard. Brown University; Estados Unidos Fil: Andreev, Andrei. Alfred Wegener Institut Helmholtz Centre for Polar and Marine Research; Alemania Fil: Bertrand, Sebastien. Ghent University; Bélgica Fil: Massaferro, Julieta. Administración de Parques Nacionales. Parque Nacional "Nahuel Huapi"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Published
2020

6. A model to predict image formation in the three-dimensional field ion microscope

Author

Nicolas Rolland, Shyam Katnagallu, Rodrigue Lardé, Benjamin Klaes, Fabien Delaroche, Stefan Parviainen, Baptiste Gault, François Vurpillot, Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-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)-Institut de Recherche sur les Matériaux Avancés (IRMA), 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)-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)-Université de Caen Normandie (UNICAEN), 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), Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Gesellschaft, Centre National de la Recherche Scientifique (CNRS)-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)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), and Normandie Université (NU)

Subjects
Image formation, Condensed Matter - Materials Science, Tomographic reconstruction, Materials science, Field (physics), Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, General Physics and Astronomy, Image processing, 01 natural sciences, 010305 fluids & plasmas, Computational physics, Characterization (materials science), [PHYS.PHYS.PHYS-COMP-PH]Physics [physics]/Physics [physics]/Computational Physics [physics.comp-ph], Hardware and Architecture, Field desorption, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Grain boundary, 010306 general physics, ComputingMilieux_MISCELLANEOUS, Field ion microscope
Abstract

Field ion microscopy (FIM) was the first technique to image individual atoms on the surface of a material. By a careful control of the field evaporation of surface atoms, the bulk of the material is exposed, and, through digital processing of a sequence of micrographs, an atomically-resolved three-dimensional reconstruction can be achieved. 3DFIM is particularly suited to the direct observation of crystalline defects that underpin the physical properties of materials: vacancies and vacancy clusters, interstitials, dislocations, or grain boundaries. Yet, further developments of 3DFIM are necessary to turn it into a routines technique. Here, we introduce first a protocol for 3DFIM image processing and subsequent tomographic reconstruction. Second, we propose a numerical model enabling simulation of the FIM imaging process. The model combines the meshless algorithm for field evaporation proposed by Rolland et al. (Robin–Rolland Model, or RRM) with fundamental aspects of the field ionization process of the gas image involved in FIM. The proposed model enables the simulation of imaging artefacts that are induced by non-regular field evaporation and by the disturbed electric field distribution near atomic defects. Our model enables more precise interpretation of 3DFIM characterization of structural defects.

Published
2020

7. Large scale mobility calculations in PEDOT (Poly(3,4-ethylenedioxythiophene)): Backmapping the coarse-grained MARTINI morphology

Author

Juan Felipe Franco-Gonzalez, Nicolas Rolland, Igor Zozoulenko, M. Modarresi, Swedish Research Council, Linköping University, Modarresi, Mohsen [0000-0002-0008-8175], Franco-Gonzalez, Juan Felipe [0000-0002-5095-5257], Zozoulenko, Igor [0000-0002-6078-3006], Modarresi, Mohsen, Franco-Gonzalez, Juan Felipe, and Zozoulenko, Igor

Subjects
Materials science, Nanostructure, General Computer Science, Stacking, General Physics and Astronomy, TOS, Coarse-grained, Bacicmapping, Multiscale calculation, Mobility [PEDOT], 02 engineering and technology, 010402 general chemistry, 01 natural sciences, PEDOT:TOS, chemistry.chemical_compound, Molecular dynamics, PEDOT:PSS, TOS [PEDOT], Teoretisk kemi, Molecule, General Materials Science, Theoretical Chemistry, Conductive polymer, Mobility, Doping, General Chemistry, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Computational Mathematics, chemistry, Mechanics of Materials, Chemical physics, 0210 nano-technology, Poly(3,4-ethylenedioxythiophene), Backmapping
Abstract

8 p.-4 fig., Designing new high performances materials based on conducting polymers necessitates the development of multiscale models to investigate the charge transport in large realistic systems. In this work, we utilize Coarse-Grained (CG) Molecular Dynamics (MD) simulations to generate morphologies of Poly(3,4-ethylenedioxythiophene) (PEDOT) doped with Tosylate (TOS) ions, and we develop a backmapping protocol to retrieve the atomistic details of the molecules afterwards. We demonstrate that the proposed protocol corrects for the nanostructure distortions induced by Coarse-Graining the system, namely a wrong density and an over-estimated stacking distance. Quantum chemical calculations are performed on the systems obtained after backmapping in order to calculate hopping rates for charge transport, and charge mobilities as a function of the PEDOT chain length and hydration level are then calculated by solving a master equation for transport. The results are identical to the calculations performed on PEDOT morphologies obtained by direct All-Atomistic (AA) MD simulations: the mobility increases with the chain length and decreases with the hydration level, this last effect being more pronounced for short chains. This definitely shows that the workflow CG MD backmapping mobility calculations is in position to calculate charge mobility in PEDOT based materials, paving the way for theoretical investigations of transport in more complex materials such as PEDOT doped with Polystyrene Sulfonate (PSS)., This research was funded by KAW foundation grant Tail of the Sun,and the Swedish Research Council Grant No. 2016-05990 and 2017-04474, and the Advanced Functional Material center at Linköping University.

Published
2020

8. New Patchy Particle Model with Anisotropic Patches for Molecular Dynamics Simulations: Application to a Coarse-Grained Model of Cellulose Nanocrystal

Author

Aleksandar Y. Mehandzhiyski, Nicolas Rolland, Igor Zozoulenko, Mathieu Linares, and Mohit Garg

Subjects
Range (particle radiation), Materials science, 010304 chemical physics, Monte Carlo method, Complex system, Biophysics, 01 natural sciences, Biofysik, Computer Science Applications, Molecular dynamics, Nanocrystal, Macroscopic scale, Chemical physics, 0103 physical sciences, Particle, Physical and Theoretical Chemistry, Anisotropy
Abstract

Self-assembly is ubiquitous in nature and underlies the formation of many complex systems from the molecular to the macroscopic scale. Kern-Frenkel-like patchy particles are powerful models to investigate this phenomenon by computational methods such as Monte Carlo or molecular dynamics simulations. However, in these models the interactions are mediated by circular patches at the particle surface, which can be hardly mapped to realistic systems, containing for instance faceted particles with rectangular surfaces. In this paper we extend the model to take into account such geometries, and we use it to build a supra coarse-grained model of the cellulose nanocrystal where the interactions are parametrized against all-atomistic molecular dynamics simulations. The formation of cholesteric ribbons and defects in cholesteric droplets of the cellulose nanocrystal are investigated and confirm experimental behavior reported in the literature. The flexibility of this new patchy particle model makes it a powerful tool to develop supra coarse-grained models of self-assembly for large space and time scales and should find a broad range of applications for self-assembly in chemical and biological systems. Funding Agencies|Swedish Research CouncilSwedish Research Council [2016-05990]; Peter Wallenberg Foundation; Troedsson foundation; Digital Cellulose Center; Advanced Functional Material Center at Linkoping University; SeRC (Swedish e-Science Research Center); Wallenberg Wood Science Center

Published
2020

9. Author Correction: A global database of Holocene paleotemperature records

Author

Manuel Chevalier, Deborah Khider, Magaly Caniupán, Julieta Massaferro, Manuel Bringué, Marcela Sandra Tonello, Scott A. Reinemann, Ian R. Walker, Elena A. Ilyashuk, Walter Finsinger, Stephen J. Roberts, Andrew P. Rees, Mathew Fox, Pol Tarrats, Les C. Cwynar, Karen J. Taylor, Emma J. Pearson, Steve Juggins, John M. Fegyveresi, Elizabeth K. Thomas, David F. Porinchu, Anais Orsi, Nicholas P. McKay, Boris P. Ilyashuk, Oliver Heiri, Lukas Jonkers, Thomas Brussel, Vincent Montade, Eugene R. Wahl, Sakari Salonen, Darrell S. Kaufman, Martin Grosjean, Boris K. Biskaborn, Olivier Cartapanis, Tomi P. Luoto, Naomi Holmes, Cody C. Routson, Reinhard Pienitz, Brian M. Chase, Samuel L Jaccard, Louise C. Foster, Christoph Dätwyler, Angela Self, Kira Rehfeld, Aaron P. Potito, Stefan Engels, Andrei Andreev, Markus Heinrichs, Julien Emile-Geay, Nicolas Rolland, Valerie van den Bos, Jeremiah Marsicek, Mónika Tóth, Carrie Morrill, Gaute Velle, Bryan G. Mark, Andria Dawson, Mateusz Płóciennik, Konrad Gajewski, Jianyong Li, Isabelle Larocque-Tobler, Barbara Stenni, Paola Moffa-Sanchez, Liudmila Syrykh, Enlou Zhang, Shyhrete Shala, André F. Lotter, Jessica E. Tierney, Karin A. Koinig, Sebastien Bertrand, Anne de Vernal, Enikö Magyari, Petr Pařil, Matthew Peros, Snezhana Zhilich, Richard S. Vachula, M. P. Erb, Marie Claude Fortin, Krystyna M. Saunders, Elena Novenko, Larisa Nazarova, Peter G. Langdon, Yarrow Axford, Janet M. Wilmshurst, Heikki Seppä, Jeannine Marie St-Jacques, Angelica Feurdean, Philipp Sommer, Stephen J. Brooks, Anson W. Mackay, Sonja Hausmann, Steven B. Malevich, and Basil A. S. Davis

Subjects
Statistics and Probability, lcsh:Q, Physical geography, Library and Information Sciences, Statistics, Probability and Uncertainty, Author Correction, lcsh:Science, Geology, Holocene, Computer Science Applications, Education, Information Systems
Abstract

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Published
2020

10. Understanding morphology-mobility dependence in PEDOT:Tos

Author

Nicolas Rolland, Riccardo Volpi, Juan Felipe Franco-Gonzalez, Igor Zozoulenko, and Mathieu Linares

Subjects
chemistry.chemical_classification, Morphology (linguistics), Materials science, Physics and Astronomy (miscellaneous), Field (physics), business.industry, Nanotechnology, 02 engineering and technology, Polymer, Conjugated system, 010402 general chemistry, 021001 nanoscience & nanotechnology, Polymer Chemistry, 01 natural sciences, 0104 chemical sciences, Semiconductor, PEDOT:PSS, chemistry, Polymerkemi, General Materials Science, Charge carrier, Inorganic materials, 0210 nano-technology, business
Abstract

The potential of conjugated polymers to compete with inorganic materials in the field of semiconductor is conditional on fine-tuning of the charge carriers mobility. The latter is closely related to the material morphology, and various studies have shown that the bottleneck for charge transport is the connectivity between well-ordered crystallites, with a high degree of pi-pi stacking, dispersed into a disordered matrix. However, at this time there is a lack of theoretical descriptions accounting for this link between morphology and mobility, hindering the development of systematic material designs. Here we propose a computational model to predict charge carriers mobility in conducting polymer PEDOT depending on the physicochemical properties of the system. We start by calculating the morphology using molecular dynamics simulations. Based on the calculated morphology we perform quantum mechanical calculation of the transfer integrals between states in polymer chains and calculate corresponding hopping rates using the Miller-Abrahams formalism. We then construct a transport resistive network, calculate the mobility using a mean-field approach, and analyze the calculated mobility in terms of transfer integrals distributions and percolation thresholds. Our results provide theoretical support for the recent study [Noriega et al., Nat Mater 12, 1038 (2013)] explaining why the mobility in polymers rapidly increases as the chain length is increased and then saturates for sufficiently long chains. Our study also provides the answer to the long-standing question whether the enhancement of the crystallinity is the key to designing high-mobility polymers. We demonstrate, that it is the effective pi-pi stacking, not the long-range order that is essential for the material design for the enhanced electrical performance. This generic model can compare the mobility of a polymer thin film with different solvent contents, solvent additives, dopant species or polymer characteristics, providing a general framework to design new high mobility conjugated polymer materials. Funding Agencies|Swedish Energy Agency [38332-1, 43561-1]; Knut and Alice Wallenberg Foundation through the project The Tail of the Sun; Swedish Research Council via "Research Environment grant" [2016-05990]; SeRC (Swedish e-Science Research Center)

Published
2018

11. Reconstructing APT Datasets: Challenging the Limits of the Possible

Author

David Zanuttini, James S. Speck, Baishaikhi Mazumder, Nicolas Rolland, Constantinos Hatzoglou, Stefan Parviainen, François Vurpillot, Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-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)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), University at Buffalo [SUNY] (SUNY Buffalo), State University of New York (SUNY), Materials Department and Materials Research Laboratory, University of California, University of California, Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-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)-Institut de Recherche sur les Matériaux Avancés (IRMA), 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)-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)-Université de Caen Normandie (UNICAEN), 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), and University of California (UC)

Subjects
010302 applied physics, Diffraction, [PHYS]Physics [physics], Reconstruction algorithm, 02 engineering and technology, Atom probe, 021001 nanoscience & nanotechnology, 01 natural sciences, Atomic units, Computational physics, law.invention, law, Electric field, 0103 physical sciences, Atom, 0210 nano-technology, Instrumentation, Image resolution, Field ion microscope
Abstract

International audience; Atom probe tomography (APT) has been successfully used in materials science for several decades for probing local compositional variations. In metals, the capacity to measure reliable composition at the nanoscale in 3D was successfully demonstrated in the early nineties [I, 2]. By using a few geometric ingredients, a reconstruction recipe was proposed at this time that surprisingly produced on selected materials, 3D images with an atomic scale precision of the distribution of atoms with elemental identification [3). The ability to localize precisely the 3-D coordinates of individual atoms in direct space of materials is expected to find important applications in materials science and engineering, nanoscience, physics and chemistry. It is particularly crucial in semiconductor industry, to design optical devices or electronic devices, such as light-emitting diodes (LEDs), or transistors.This ideal picture of near-perfect 3D microscope however faces two issues. First, the precision of images may vary strongly from one material to another. Compared to an optical or an electron microscope, the spatial resolution loss is not diffraction limited, since image is produced from the inverse projection of ion trajectories, ions been produced by field evaporation of surface atoms. Precision is perturbed by slight deviations of the trajectories of ions from their initial positions at the specimen surace to the ion detector. A real understanding of this trajectory taking into account first the quantum interaction of atoms/ions with the specimen surface under the presence of the strong electric field existing on the surface is mandatory. The interplay between quantum processes, and more classical deviations induced by the distribution of the electric field close to the surface is extremely complex. In metals, most of the deviations thought to be induced by the field, as it was recently demonstrated experimentally by field ion microscopy in tungsten (fig. I). In oxides, quantum effects such as in-flight dissociation of molecules may degrade significantly the spatial precision (fig. 2) [4]. The second issue concerns the global distortions induced by the presence in the sample of phases very different in term of the critical fields required to extract surface atoms. This is a current case when analyzing devices composed of complex structures of metals, oxides and semiconductors materials. The surface of the sample ideally modelled with a constant curvature radius evolves dynamically under the process of field evaporation in a complex 3D surface. The direct consequence is the presence of distortions in the projected image. After the evaporation of each atom, the field distribution around the sample must be evaluated, to understand the projection law that should necessary be taken into account to generate an accurate reconstruction [5, 6). To overcome this cumbersome calculation, an alternative model, much simpler, was developed to reproduce the imaging process in simple configurations. In multilayers systems, it was demonstrated that most of the distortions could be reduced using a fast and efficient reconstruction algorithm that predicts the analytical shape of the emitting surface all along the evaporation process [7]. If a complementary technique can be used on the same sample to verify the morphology or provide complementary information before APT analysis, then this can also greatly…

Published
2017

12. Correlative Investigations by HAADF-STEM and Atom Probe Tomography

Author

Williams Lefebvre, Florian Moyon, Antoine Normand, Nicolas Rolland, Ivan Blum, Auriane Etienne, Celia Castro, Fabien Cuvilly, Lorenzo Mancini, Isabelle Mouton, Lorenzo Rigutti, François Vurpillot, Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-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)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-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)-Institut de Recherche sur les Matériaux Avancés (IRMA), 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)-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)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2016

13. Accuracy of analyses of microelectronics nanostructures in atom probe tomography

Author

François Vurpillot, Sébastien Duguay, Didier Blavette, Robert Estivill, Nicolas Rolland, Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-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)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), STMicroelectronics [Crolles] (ST-CROLLES), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-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)-Institut de Recherche sur les Matériaux Avancés (IRMA), 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)-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)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Permittivity, Microscope, Materials science, nanostructure, Nanotechnology, 02 engineering and technology, Atom probe, Dielectric, 01 natural sciences, law.invention, Optics, law, 0103 physical sciences, Materials Chemistry, Microelectronics, Electrical and Electronic Engineering, Metal gate, atom probe, 010302 applied physics, [PHYS]Physics [physics], business.industry, Transistor, 021001 nanoscience & nanotechnology, Condensed Matter Physics, simulation, Electronic, Optical and Magnetic Materials, Semiconductor, metrology, 0210 nano-technology, business
Abstract

International audience; \textcopyright 2016 IOP Publishing Ltd. The routine use of atom probe tomography (APT) as a nano-analysis microscope in the semiconductor industry requires the precise evaluation of the metrological parameters of this instrument (spatial accuracy, spatial precision, composition accuracy or composition precision). The spatial accuracy of this microscope is evaluated in this paper in the analysis of planar structures such as high-k metal gate stacks. It is shown both experimentally and theoretically that the in-depth accuracy of reconstructed APT images is perturbed when analyzing this structure composed of an oxide layer of high electrical permittivity (higher-k dielectric constant) that separates the metal gate and the semiconductor channel of a field emitter transistor. Large differences in the evaporation field between these layers (resulting from large differences in material properties) are the main sources of image distortions. An analytic model is used to interpret inaccuracy in the depth reconstruction of these devices in APT.

Published
2016

14. A Meshless Algorithm to Model Field Evaporation in Atom Probe Tomography

Author

Didier Blavette, Sébastien Duguay, François Vurpillot, Nicolas Rolland, Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-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)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-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)-Institut de Recherche sur les Matériaux Avancés (IRMA), 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)-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)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Physics, Surface (mathematics), [PHYS]Physics [physics], Field (physics), Point particle, Evaporation, Charge density, 02 engineering and technology, Atom probe, 021001 nanoscience & nanotechnology, 01 natural sciences, law.invention, law, Ionization, 0103 physical sciences, Atom, 0210 nano-technology, Instrumentation, Algorithm, ComputingMilieux_MISCELLANEOUS
Abstract

An alternative approach for simulating the field evaporation process in atom probe tomography is presented. The model uses the electrostatic Robin’s equation to directly calculate charge distribution over the tip apex conducting surface, without the need for a supporting mesh. The partial ionization state of the surface atoms is at the core of the method. Indeed, each surface atom is considered as a point charge, which is representative of its evaporation probability. The computational efficiency is ensured by an adapted version of the Barnes–Hut N-body problem algorithm. Standard desorption maps for cubic structures are presented in order to demonstrate the effectiveness of the method.

Published
2015

15. Dynamic evolution and fracture of multilayer field emitters in atom probe tomography: a new interpretation

Author

François Vurpillot, Nicolas Rolland, Didier Blavette, Sébastien Duguay, Groupe de physique des matériaux (GPM), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), 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)-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)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
010302 applied physics, Surface (mathematics), [PHYS]Physics [physics], Materials science, Field (physics), Delaunay triangulation, Evaporation, Geometry, Nanotechnology, 02 engineering and technology, Atom probe, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Curvature, 01 natural sciences, Electronic, Optical and Magnetic Materials, law.invention, law, 0103 physical sciences, Constant-mean-curvature surface, 0210 nano-technology, Instrumentation, Common emitter
Abstract

International audience; Since Atom Probe Tomography reconstruction is based on ion back projection onto the emitter surface, understanding of the evolution dynamics of the tip shape is essential to get an accurate picture of the initial sample. In this article, an analytical approach is presented to dynamically describe the morphology evolution of complex multilayer structures during field evaporation. The model is mostly founded on the common continuity hypothesis, except for the classical hemispherical description of the tip apex, which is extended to a wider class of a constant mean curvature surface of revolution, the Delaunay surfaces. The results obtained from this approach are comparable with standard numerical simulations, but the analytical character of the model gives more insight into the principles driving the emitter morphology. In particular, a complete picture of curvature evolution during the transition from one layer to another is provided. Additionally, a field evaporation threshold for tip fracture in a bilayer sample is highlighted.

Published
2015

16. Probabilistic programs as spreadsheet queries

Author

Marcin Szymczak, Nicolas Rolland, Daniel Tarlow, Andrew D. Gordon, Thore Graepel, Claudio V. Russo, and Johannes Borgström

Subjects
Computer science, Programming language, Computer Sciences, Probabilistic logic, Computer Science::Software Engineering, Inference, Statistical model, Computer Science::Human-Computer Interaction, computer.software_genre, Dependent type, Computer Science::Computers and Society, Datavetenskap (datalogi), Embedding, Probabilistic programming language, computer, Computer Science::Databases, Coding (social sciences)
Abstract

We describe the design, semantics, and implementation of a probabilistic programming language where programs are spreadsheet queries. Given an input database consisting of tables held in a spreadsheet, a query constructs a probabilistic model conditioned by the spreadsheet data, and returns an output database determined by inference. This work extends probabilistic programming systems in three novel aspects: (1) embedding in spreadsheets, (2) dependently typed functions, and (3) typed distinction between random and query variables. It empowers users with knowledge of statistical modelling to do inference simply by editing textual annotations within their spreadsheets, with no other coding.

Published
2015

17. Three dimensional imaging and analysis of a single nano-device at the ultimate scale using correlative microscopy techniques

Author

G. Audoit, R. Serra, Pierre Morin, Nicolas Rolland, François Vurpillot, P. Gouraud, Jean-Paul Barnes, Didier Blavette, Adeline Grenier, David Cooper, Sébastien Duguay, Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Groupe de physique des matériaux (GPM), Centre National de la Recherche Scientifique (CNRS)-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)-Normandie Université (NU)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), STMicroelectronics [Crolles] (ST-CROLLES), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-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)-Institut de Recherche sur les Matériaux Avancés (IRMA), 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)-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)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), and Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Physics and Astronomy (miscellaneous), Physics::Medical Physics, 02 engineering and technology, Electron, Iterative reconstruction, Atom probe, 01 natural sciences, Atomic units, law.invention, Optics, law, 0103 physical sciences, Microscopy, Physics::Atomic and Molecular Clusters, Physics::Atomic Physics, 010302 applied physics, Condensed Matter::Quantum Gases, [PHYS]Physics [physics], business.industry, 021001 nanoscience & nanotechnology, Electron tomography, Nanometre, Tomography, Atomic physics, 0210 nano-technology, business
Abstract

International audience; The analysis of a same sample using nanometre or atomic-scale techniques is fundamental to fully understand device properties. This is especially true for the dopant distribution within last generation nano-transistors such as MOSFET or FINFETs. In this work, the spatial distribution of boron in a nano-transistor at the atomic scale has been investigated using a correlative approach combining electron and atom probe tomography. The distortions present in the reconstructed volume using atom probe tomography have been discussed by simulations of surface atoms using a cylindrical symmetry taking into account the evaporation fields. Electron tomography combined with correction of atomic density was used so that to correct image distortions observed in atom probe tomography\backslashnreconstructions. These corrected atom probe tomography\backslashnreconstructions then enable a detailed boron\backslashndoping analysis of the device.

Published
2015

18. Tabular: A Schema-driven Probabilistic Programming Language

Author

John Guiver, Johannes Borgström, Claudio V. Russo, Nicolas Rolland, Andrew D. Gordon, and Thore Graepel

Subjects
Relational database, Computer science, Programming language, Computer Sciences, Formal semantics (linguistics), probabilistic programming, Statistical model, Notation, Bayesian inference, Missing data, computer.software_genre, Computer Graphics and Computer-Aided Design, model-learner pattern, Datavetenskap (datalogi), machine learning, Ranking, Semantics of logic, Schema (psychology), relational data, Probabilistic programming language, bayesian reasoning, Cluster analysis, Bayesian reasoning, computer, Software
Abstract

We propose a new kind of probabilistic programming language for machine learning. We write programs simply by annotating existing relational schemas with probabilistic model expressions. We describe a detailed design of our language, Tabular, complete with formal semantics and type system. A rich series of examples illustrates the expressiveness of Tabular. We report an implementation, and show evidence of the succinctness of our notation relative to current best practice. Finally, we describe and verify a transformation of Tabular schemas so as to predict missing values in a concrete database. The ability to query for missing values provides a uniform interface to a wide variety of tasks, including classification, clustering, recommendation, and ranking.

Published
2014

19. The use of high-resolution gridded climate data in the development of chironomid-based inference models from remote areas

Author

David F. Porinchu, Nicolas Rolland, and Isabelle Larocque

Subjects
Meteorology, Sampling (statistics), Climate change, Inference, 910 Geography & travel, Aquatic Science, Latitude, Data set, Climatology, Paleoclimatology, Environmental science, Simple linear regression, Physics::Atmospheric and Oceanic Physics, Reliability (statistics), Earth-Surface Processes
Abstract

The development of chironomid-based air temperature inference models in high latitude regions often relies on limited spatial coverage of meteorological data and/or on punctual measurements of water temperature at the time of sampling. The use of simple linear regression to relate air temperature and latitude was until recently the best method to characterize the air temperature gradient along a latitudinal gradient. However, recent studies have used high-resolution gridded climate data to develop new chironomid-based air temperature inference models. This innovative approach has, however, never been further analyzed to test its reliability. This study presents a method using ArcGIS® to extract air temperatures from a high-resolution global gridded climate data set (New et al. 2002) and to incorporate these new data in a variety of chironomid-based air temperature inference models to test their performance. Results suggest that this method is reliable and produces better estimates of air temperature and will be helpful in the development of further quantitative air temperature inference models in remote areas.

Published
2009

20. Mechanisms of Intra-Organisational Knowledge Transfer: The Case of a Global Technology Firm

Author

Alexandre Perrin and Nicolas Rolland

Subjects
Engineering, Knowledge management, business.industry, Strategy and Management, General Business, Management and Accounting, Unit (housing), Interpersonal ties, Documentation, Action (philosophy), Strategic business unit, business, Adaptation (computer science), Knowledge transfer, Interactive media
Abstract

This paper develops three mechanisms to facilitate knowledge transfer within a global technology firm. Documentation helps to codify knowledge and make it less ambiguous. Technology is used as an interactive media to spread the message codified whereas a face-to-face community develops social ties among different business units among the firm. After monitoring the impact of each mechanism we discuss the need for adaptation and the factors influencing this adaptation. The results give rise to the prevalent role of the manager of the business unit whose action affects both the properties of the unit and the relationships with other units.

Published
2007

21. Impact of local electrostatic field rearrangement on field ionization.

Author

Shyam Katnagallu, Michal Dagan, Stefan Parviainen, Ali Nematollahi, Blazej Grabowski, Paul A J Bagot, Nicolas Rolland, Jörg Neugebauer, Dierk Raabe, François Vurpillot, Michael P Moody, and Baptiste Gault

Subjects
ELECTROSTATIC fields, FIELD ionization, FIELD ion microscopy
Abstract

Field ion microscopy allows for direct imaging of surfaces with true atomic resolution. The high charge density distribution on the surface generates an intense electric field that can induce ionization of gas atoms. We investigate the dynamic nature of the charge and the consequent electrostatic field redistribution following the departure of atoms initially constituting the surface in the form of an ion, a process known as field evaporation. We report on a new algorithm for image processing and tracking of individual atoms on the specimen surface enabling quantitative assessment of shifts in the imaged atomic positions. By combining experimental investigations with molecular dynamics simulations, which include the full electric charge, we confirm that change is directly associated with the rearrangement of the electrostatic field that modifies the imaging gas ionization zone. We derive important considerations for future developments of data reconstruction in 3D field ion microscopy, in particular for precise quantification of lattice strains and characterization of crystalline defects at the atomic scale. [ABSTRACT FROM AUTHOR]

Published
2018
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