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34 results on '"Institute of Physics [Warsaw] (IFPAN)"'

1. Mapping the deformability of natural and designed cellulosomes in solution

Author

Jonathan Dorival, Sarah Moraïs, Aurore Labourel, Bartosz Rozycki, Pierre-Andre Cazade, Jérôme Dabin, Eva Setter-Lamed, Itzhak Mizrahi, Damien Thompson, Aurélien Thureau, Edward A. Bayer, Mirjam Czjzek, Laboratoire de Biologie Intégrative des Modèles Marins (LBI2M), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Station biologique de Roscoff (SBR), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Weizmann Institute of Science [Rehovot, Israël], Ben-Gurion University of the Negev (BGU), Biodiversité et Biotechnologie Fongiques (BBF), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), University of Limerick (UL), Beamline SWING, Synchrotron SOLEIL, Synchrotron SOLEIL (SSOLEIL), and Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Scaffoldins, [SDV.BBM.BS]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Structural Biology [q-bio.BM], Renewable Energy, Sustainability and the Environment, Designer cellulosomes, Molecular modeling, SAXS, Self-assembly, Management, Monitoring, Policy and Law, Applied Microbiology and Biotechnology, Bionanomachinery, Multi-enzyme complex, Energy (miscellaneous), Biotechnology
Abstract

Background Natural cellulosome multi-enzyme complexes, their components, and engineered ‘designer cellulosomes’ (DCs) promise an efficient means of breaking down cellulosic substrates into valuable biofuel products. Their broad uptake in biotechnology relies on boosting proximity-based synergy among the resident enzymes, but the modular architecture challenges structure determination and rational design. Results We used small angle X-ray scattering combined with molecular modeling to study the solution structure of cellulosomal components. These include three dockerin-bearing cellulases with distinct substrate specificities, original scaffoldins from the human gut bacterium Ruminococcus champanellensis (ScaA, ScaH and ScaK) and a trivalent cohesin-bearing designer scaffoldin (Scaf20L), followed by cellulosomal complexes comprising these components, and the nonavalent fully loaded Clostridium thermocellum CipA in complex with Cel8A from the same bacterium. The size analysis of Rg and Dmax values deduced from the scattering curves and corresponding molecular models highlight their variable aspects, depending on composition, size and spatial organization of the objects in solution. Conclusions Our data quantifies variability of form and compactness of cellulosomal components in solution and confirms that this native plasticity may well be related to speciation with respect to the substrate that is targeted. By showing that scaffoldins or components display enhanced compactness compared to the free objects, we provide new routes to rationally enhance their stability and performance in their environment of action.

Published
2022

3. XAFS study of bioactive Cu(II) complexes of 7-hydroxycoumarin derivatives in organic solvents

Author

Giuliana Aquilanti, Aleksandra Drzewiecka-Antonik, Keisuke Hatada, Anna Wolska, Marcin T. Klepka, Pawel Rejmak, Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Università degli Studi di Camerino (UNICAM), Laboratori Nazionali di Frascati (LNF), Istituto Nazionale di Fisica Nucleare (INFN), Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Elettra Sincrotrone Trieste, Experimental research was funded from the Polish National Science Centre (Grant No. UMO-2012/07/D/ST5/02251). This research was supported in part by PL-Grid Infrastructure. Financial support from the EU FP7 EAgLE project under the grant agreement REGPOT-CT-2013-316014 is gratefully acknowledged., European Project: 316014,EC:FP7:REGPOT,FP7-REGPOT-2012-2013-1,EAGLE(2013), Università degli Studi di Camerino = University of Camerino (UNICAM), and Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Extended X-ray absorption fine structure, Absorption spectroscopy, Dimethyl sulfoxide, General Physics and Astronomy, 02 engineering and technology, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, 3. Good health, X-ray absorption fine structure, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Solvent, chemistry.chemical_compound, chemistry, Polymer chemistry, Molecule, Organic chemistry, Dimethylformamide, [CHIM.COOR]Chemical Sciences/Coordination chemistry, Density functional theory, Physical and Theoretical Chemistry, 0210 nano-technology
Abstract

International audience; We characterize the structure of two Cu(II) complexes of 7-hydroxycoumarins in organic solvents. The solvents are, dimethyl sulfoxide and dimethylformamide. X-ray absorption spectroscopy together with density functional theory calculations are employed to identify the structural changes induced by the two solvents in comparison to the solid form of complexes. We show that the structure of the Cu(II) complexes is modified depending on the solvent and we propose the geometry of the complexes molecule.

Published
2017

4. Nonequilibrium atomistic molecular dynamics simulation of tubular nanomotor propelled by bubble propulsion

Author

Junmei Wang, Phuong H. Nguyen, Mai Suan Li, Philippe Derreumaux, Viet Hoang Man, Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Laboratoire de biochimie théorique [Paris] (LBT (UPR_9080)), Université Paris Diderot - Paris 7 (UPD7)-Institut de biologie physico-chimique (IBPC), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut de biologie physico-chimique (IBPC (FR_550)), and Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)

Subjects
Materials science, 010304 chemical physics, Bubble, General Physics and Astronomy, Mechanics, Propulsion, 010402 general chemistry, 7. Clean energy, 01 natural sciences, 0104 chemical sciences, Pipe flow, Quantitative Biology::Subcellular Processes, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, ARTICLES, Molecular dynamics, 0103 physical sciences, Particle, [CHIM]Chemical Sciences, Liquid bubble, Physical and Theoretical Chemistry, Nanomotor, Displacement (fluid), ComputingMilieux_MISCELLANEOUS
Abstract

We develop a molecular nanoscaled model for tubular motors propelled by bubble propulsion. The motor is modeled by a carbon nanotube, and the bubble is represented by a particle interacting with water by a time-dependent potential. Effects of liquid viscosity, fuel concentration, geometry, and size of the tube on the performance of the motor are effectively encoded into two parameters: time scales of the bubble expansion and bubble formation. Our results are qualitatively consistent with experimental data of much larger motors. Simulations suggest that (i) the displacement of the tube is optimized if two time scales are as short as possible, (ii) the compromise between the performance and fuel consumption is achieved if the bubble formation time is shorter than the velocity correlation time of the tube, (iii) the motor efficiency is higher with slow expansion, short formation of the bubble than fast growth but long formation time, and (iv) the tube is propelled by strong forces on the order of mN, reaching high speeds up to ∼60 m/s. Our simulation may be useful for refining and encouraging future experimental work on nanomotors having the size of a few nanometers. The tiny size and high speed motors could have great potential applications in real life.

Published
2019

5. Interaction mechanism between the focused ultrasound and lipid membrane at the molecular level

Author

Junmei Wang, Philippe Derreumaux, Mai Suan Li, Viet Hoang Man, Phuong H. Nguyen, Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Laboratoire de biochimie théorique [Paris] (LBT (UPR_9080)), Université Paris Diderot - Paris 7 (UPD7)-Institut de biologie physico-chimique (IBPC), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut de biologie physico-chimique (IBPC (FR_550)), and Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)

Subjects
Materials science, medicine.medical_treatment, Lipid Bilayers, General Physics and Astronomy, Molecular Dynamics Simulation, 010402 general chemistry, 01 natural sciences, Cell membrane, ARTICLES, Membrane Lipids, Motion, Molecular dynamics, Molecular level, 0103 physical sciences, medicine, [CHIM]Chemical Sciences, Physical and Theoretical Chemistry, Lipid bilayer, Pressure gradient, ComputingMilieux_MISCELLANEOUS, 010304 chemical physics, Therapeutic ultrasound, business.industry, Ultrasound, 0104 chemical sciences, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Membrane, medicine.anatomical_structure, Ultrasonic Waves, Phosphatidylcholines, Biophysics, business
Abstract

Focused ultrasound (FUS) has a wide range of medical applications. Nowadays, the diagnostic and therapeutic ultrasound procedures are routinely used; effects of ultrasound on biological systems at the molecular level are, however, not fully understood. Experimental results on the interaction of the cell membrane, a simplest but important system component, with ultrasound are controversial. Molecular dynamics (MD) simulations could provide valuable insights, but there is no single study on the mechanism of the FUS induced structural changes in cell membranes. With this in mind, we develop a simple method to include FUS into a standard MD simulation. Adopting the 1,2-dioleoyl-sn-glycero-3-phosphocholine lipid membrane as a representative model described by the MARTINI coarse-grained force field, and using experimental values of the ultrasound frequency and intensity, we show that the heat and bubble cavitation are not the primary direct mechanisms that cause structural changes in the membrane. The spatial pressure gradients between the focused and free regions and between the parallel and perpendicular directions to the membrane are the origin of the mechanism. These gradients force lipids to move out of the focused region, forming a lipid flow along the membrane diagonal. Lipids in the free region move in the opposite direction due to the conservation of the total momentum. These opposite motions create wrinkles along the membrane diagonal at low FUS intensities and tear up the membrane at high FUS intensities. Once the membrane is torn up, it is not easy to reform. The implication of our findings in the FUS-induced drug delivery is discussed in some detail.

Published
2019

6. The critical role of N-vacancy on chemical composition fluctuations and degradation of InAlN layer

Author

Sławomir Kret, Marie Pierre Chauvat, Cedric Lacam, Sylvain Delage, Pierre Ruterana, Ranim Mohamad, Viwanou Hounkpati, Piero Gamarra, Jun Chen, Centre de recherche sur les Ions, les MAtériaux et la Photonique (CIMAP - UMR 6252), Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Caen Normandie (UNICAEN), Normandie Université (NU), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Alcatel-Thales III-V Lab (III-V Lab), THALES, Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), THALES [France], Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics, Polska Akademia Nauk (PAN), Laboratoire de Recherches de THOMSON-CSF (LCR-THOMSON-CSF), Thomson, État Mécanique et Microstructure des Matériaux (E3M), Institut de Recherche en Génie Civil et Mécanique (GeM), Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, and Université de Nantes (UN)-Université de Nantes (UN)-École Centrale de Nantes (ECN)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Indium nitride, Fabrication, Materials science, Alloy, General Physics and Astronomy, chemistry.chemical_element, 02 engineering and technology, engineering.material, 01 natural sciences, law.invention, chemistry.chemical_compound, law, Vacancy defect, Lattice (order), 0103 physical sciences, [CHIM.CRIS]Chemical Sciences/Cristallography, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Chemical composition, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, [PHYS.PHYS]Physics [physics]/Physics [physics], business.industry, Transistor, [CHIM.MATE]Chemical Sciences/Material chemistry, 021001 nanoscience & nanotechnology, chemistry, engineering, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, 0210 nano-technology, business, Indium
Abstract

Due to its intrinsic properties and the possible lattice match to GaN, InAlN is expected to allow the fabrication of optimal high electron mobility transistors for high power and high frequency applications. However, the crystal quality of InAlN nearly lattice-matched to GaN degrades when the layer thickness is increased, and this is a strong limitation for the fabrication of devices in which thick barriers need to be used. In this work, we have carried out a detailed theoretical investigation of the behavior of indium atoms in the alloy. It is clearly shown that in the presence of nitrogen vacancies, which are common defects in these materials, indium nitride clusters will present excess formation energy up to diameters around 1.4 nm. In parallel, Z-contrast TEM observations close to the InAlN/GaN interface show that 2–5 nm size indium rich areas form and are systematically connected to the vertical degradation channels. This is at variance with published results, which concluded that the observed degradation was exclusively either due to the underlying threading dislocations or due to a characteristic three-dimensional growth mode.

Published
2019

7. Photoinduced effects on the magnetic properties of the (Fe0.2Cr0.8)1.5[Cr(CN)6] Prussian blue analogue

Author

I.A. Kowalik, Juan José de Miguel, M. A. Niño, Helena Prima-García, Dimitri Arvanitis, Francisco M. Romero, Eugenio Coronado, Juan P. Prieto-Ruiz, Francisco Jesús Luque, Corine Mathonière, Rodolfo Miranda, Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Instituto de Ciencia Molecular (ICMol), Universitat de València (UV), Instituto IMDEA Nanociencia [Madrid], Instituto Imdea Nanociencia, Department of Physics and Astronomy [Uppsala], Uppsala University, Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Condensed Matter Physics Center (IFIMAC), Instituto de Física de Materiales 'Nicolás Cabrera', Universidad Autonoma de Madrid (UAM), and This work was financed by the EU (COST Action MOLSPIN (CA15128)) and by the Spanish MINECO through Network NANOMOLNet (MAT2016-61989-REDC), through Grants MAT2013-47869-C4-3-P and FIS2016-74893-P for the UAM group, and through the Unit of Excellence María de Maeztu MDM-2015-0538 and Grant MAT2017-89993, the Polish National Centre through Grant 2011/03/D/ST3/02654 , the European CALIPSO Programme and the Carl Tryggers foundation for Science Research (contracts CTS 14 : 32 and 16 : 32).

Subjects
Solid-state chemistry, Prussian blue, Materials science, Magnetic moment, Magnetism, 02 engineering and technology, General Chemistry, [CHIM.MATE]Chemical Sciences/Material chemistry, 010402 general chemistry, 021001 nanoscience & nanotechnology, Photochemistry, 01 natural sciences, 0104 chemical sciences, Ion, chemistry.chemical_compound, Photosensitivity, chemistry, Materials Chemistry, 0210 nano-technology, Ternary operation, Isomerization
Abstract

International audience; One of the most attractive characteristics of some Prussian blue derivatives is the sensitivity of their magnetic properties to the irradiation with light. In this work photoinduced effects in the (Fe0.2Cr0.8)1.5[Cr(CN)6]·15H2O PBA have been studied by means of X-ray-based spectroscopies and magnetometry. It is found that the photosensitivity of this compound is mostly centred on the Fe cations: the exposure to green light induces a transfer of electrons from them to the Cr that provokes a reversal of the previously existing linkage isomerization and increases the elastic strain caused by the misfit of the unit cells of the Fe–NC–Cr and Cr–NC–Cr sublattices. The green light also quenches the magnetism of the FeII high-spin (HS) ions present in the sample and reduces the magnetic moments of most of the Cr cations except for CrII HS. Our study highlights the important role played by the mismatch between the unit cells of the coexisting sub-lattices in ternary Prussian blue analogues.

Published
2019

8. Molecular Mechanism of the Cell Membrane Pore Formation Induced by Bubble Stable Cavitation

Author

Junmei Wang, Mai Suan Li, Viet Hoang Man, Nguyen-Thi Van-Oanh, Phan Minh Truong, Philippe Derreumaux, Phuong H. Nguyen, Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Laboratoire de Chimie Physique D'Orsay (LCPO), Université Paris-Sud - Paris 11 (UP11)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de biochimie théorique [Paris] (LBT (UPR_9080)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut de biologie physico-chimique (IBPC (FR_550)), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Université Paris Diderot - Paris 7 (UPD7)-Institut de biologie physico-chimique (IBPC), and Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Bubble, Molecular Dynamics Simulation, 010402 general chemistry, 01 natural sciences, Cell membrane, Molecular dynamics, 0103 physical sciences, Materials Chemistry, Shear stress, medicine, [SDV.BBM]Life Sciences [q-bio]/Biochemistry, Molecular Biology, Physical and Theoretical Chemistry, Lipid bilayer, ComputingMilieux_MISCELLANEOUS, Microbubbles, 010304 chemical physics, Cell Membrane, 0104 chemical sciences, Surfaces, Coatings and Films, Membrane, medicine.anatomical_structure, Cavitation, Phosphatidylcholines, Biophysics
Abstract

Microbubbles in combination with ultrasound provide a new and promising way to deliver drugs into living cells. It is believed that the stable vibration or the collapse of the bubbles under ultrasound are the two main mechanisms that induce the formation of pores in the cell membranes, through which drugs may get inside the cell cytoplasm. The bubble collapse hypothesis is not only intuitive since released shock waves can easily penetrate and create pores in the membrane, but it is also confirmed by both experiment and theory. In contrast, the molecular mechanism of stable vibration is not well-understood because of experimental difficulties resulting from the fragility of bubbles and the lack of molecular dynamics simulation studies. To obtain a better understanding of this mechanism, we developed a lipid-coated bubble model that we applied to simulate the stable cavitation of the bubble in the presence of a lipid bilayer. We show that the wall shear stress generated by the bubble vibration does not induce the membrane pore formation. Instead, the bubble fuses with the membrane and subsequent cavitation pulls lipid molecules out of the membrane, creating pores. This could help one to choose the best combination of the bubble shell materials, the ultrasound frequency, and intensity, so that the opening and closing of pores will be optimized.

Published
2018

9. Phase transitions and magnetic properties of LuFe2O4 under pressure

Author

Markovich, V., Fita, I., Wisniewski, A., Puzniak, R., Martin, Christine, Jung, G., Gorodetsky, G., Ben-Gurion University of the Negev (BGU), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Polish National Science Centre (NCN) [2014/15/B/ST3/03898, 2012/05/B/ST3/03157], Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Condensed Matter::Materials Science, Magnetic phase transitions, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, Condensed Matter::Strongly Correlated Electrons, [CHIM.MATE]Chemical Sciences/Material chemistry
Abstract

International audience; The effect of hydrostatic pressure on complex magnetic phase diagram of LuFe2O4 has been investigated by various magnetic measurements in the range of 0-12 kbar. The temperature of the ferrimagnetic (fM) transition (T-N approximate to 245 K) practically does not change with increasing pressure, while the temperature of the appearance of mixed fM and antiferromagnetic (AFM) state at similar to 200 K increases with the rate dT(C)/dP approximate to 0.8 K/kbar. Moreover, an applied pressure suppresses the magnetization, enhances the field of metamagnetic transition, and extends the range of existence of mixed fM and AFM state. Suppression of the ordered magnetic moment under pressure induces a transition from a counterclockwise (CCW) thermal hysteresis below T approximate to 220 K to a clockwise (CW) thermal hysteresis in a magnetic field H = 1 kOe. Nevertheless, field induced metamagnetic transition from mixed fM and AFM state to fM state results in a narrowing of the temperature range of thermal hysteresis and in restoring of CCW type of thermal hysteresis. As a consequence of metamagnetic transition, the thermal hysteresis completed at H = 10 kOe remains one of the CCW type under applied pressure.

Published
2017

10. Exchange bias effect in CaMn1-xRexO3

Author

Markovich, V., Fita, I., Wisniewski, A., Puzniak, R., Martin, Christine, Jung, G., Gorodetsky, G., Ben-Gurion University of the Negev (BGU), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Laboratoire de cristallographie et sciences des matériaux (CRISMAT), École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC), Polish NCN grants [2014/15/B/ST3/03898, 2012/05/B/ ST3/03157], Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Matériaux Avancés (IRMA), Normandie Université (NU)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Rouen Normandie (UNIROUEN), and Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Magnetism and Magnetic Materials, [CHIM.CRIS]Chemical Sciences/Cristallography, [CHIM]Chemical Sciences, [CHIM.MATE]Chemical Sciences/Material chemistry
Abstract

International audience; Exchange bias effect in CaMn1-xRexO3 (x

Published
2017

11. Blind prediction of homo- and hetero- protein complexes: The CASP13-CAPRI experiment

Author

Lensink, Marc F., Brysbaert, Guillaume, Nadzirin, Nurul, Velankar, Sameer, Chaleil, Raphaël A. G., Gerguri, Tereza, Bates, Paul A., Laine, Elodie, Carbone, Alessandra, Grudinin, Sergei, Kong, Ren, Liu, Ran-Ran, Xu, Xi-Ming, Shi, Hang, Chang, Shan, Eisenstein, Miriam, Karczynska, Agnieszka, Czaplewski, Cezary, Lubecka, Emilia, Lipska, Agnieszka, Krupa, Paweł, Mozolewska, Magdalena, Golon, Łukasz, Samsonov, Sergey, Liwo, Adam, Crivelli, Silvia, Pagès, Guillaume, Karasikov, Mikhail, Kadukova, Maria, Yan, Yumeng, Huang, Sheng-You, Rosell, Mireia, Rodríguez-Lumbreras, Luis A., Romero-Durana, Miguel, Díaz-Bueno, Lucía, Fernandez-Recio, Juan, Christoffer, Charles, Terashi, Genki, Shin, Woong-Hee, Aderinwale, Tunde, Maddhuri Venkata Subraman, Sai Raghavendra, Kihara, Daisuke, Kozakov, Dima, Vajda, Sandor, Porter, Kathryn, Padhorny, Dzmitry, Desta, Israel, Beglov, Dmitri, Ignatov, Mikhail, Kotelnikov, Sergey, Moal, Iain H., Ritchie, David W., Chauvot de Beauchêne, Isaure, Maigret, Bernard, Devignes, Marie-Dominique, Ruiz Echartea, Maria E., Barradas-Bautista, Didier, Cao, Zhen, Cavallo, Luigi, Oliva, Romina, Cao, Yue, Shen, Yang, Baek, Minkyung, Park, Taeyong, Woo, Hyeonuk, Seok, Chaok, Braitbard, Merav, Bitton, Lirane, Scheidman-Duhovny, Dina, Dapkūnas, Justas, Olechnovič, Kliment, Venclovas, Česlovas, Kundrotas, Petras J., Belkin, Saveliy, Chakravarty, Devlina, Badal, Varsha D., Vakser, Ilya A., Vreven, Thom, Vangaveti, Sweta, Borrman, Tyler, Weng, Zhiping, Guest, Johnathan D., Gowthaman, Ragul, Pierce, Brian G., Xu, Xianjin, Duan, Rui, Qiu, Liming, Hou, Jie, Ryan Merideth, Benjamin, Ma, Zhiwei, Cheng, Jianlin, Zou, Xiaoqin, Koukos, Panagiotis I., Roel-Touris, Jorge, Ambrosetti, Francesco, Geng, Cunliang, Schaarschmidt, Jörg, Trellet, Mikael E., Melquiond, Adrien S. J., Xue, Li, Jiménez-García, Brian, van Noort, Charlotte W., Honorato, Rodrigo V., Bonvin, Alexandre M. J. J., Wodak, Shoshana J., 0000-0003-3957-9470, 0000-0003-2759-2088, 0000-0003-0621-0925, 0000-0003-2098-5743, 0000-0001-7169-9398, 0000-0002-0294-3403, 0000-0002-4209-4565, 0000-0002-7787-8896, 0000-0002-3986-7686, 0000-0002-6163-6323, 0000-0003-4091-6614, 0000-0003-0464-4500, 0000-0002-4960-5487, 0000-0002-7035-3042, 0000-0002-1703-7796, 0000-0002-1419-9888, 0000-0002-0496-6107, 0000-0002-4215-0213, 0000-0002-5743-2934, 0000-0003-3413-806X, 0000-0002-3032-7966, 0000-0002-1409-8358, 0000-0001-7369-1322, 0000-0002-0701-6545, Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576 (UGSF), Institut National de la Recherche Agronomique (INRA)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), European Bioinformatics Institute [Hinxton] (EMBL-EBI), EMBL Heidelberg, The Francis Crick Institute [London], School of Geographical Sciences [Bristol], University of Bristol [Bristol], Biologie Computationnelle et Quantitative = Laboratory of Computational and Quantitative Biology (LCQB), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Biologie Paris Seine (IBPS), Sorbonne Université (SU)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Algorithms for Modeling and Simulation of Nanosystems (NANO-D), Inria Grenoble - Rhône-Alpes, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Laboratoire Jean Kuntzmann (LJK ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), JiangSu University, Chemical Research Support [Rehovot], Weizmann Institute of Science [Rehovot, Israël], University of Gdańsk (UG), Department of Environmental Analytics [Univ Gdańsk], Faculty of Chemistry [Univ Gdańsk], University of Gdańsk (UG)-University of Gdańsk (UG), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Department of Computer Science [Davis] (UC Davis), University of California [Davis] (UC Davis), University of California-University of California, Moscow Institute of Physics and Technology [Moscow] (MIPT), Huazhong University of Science and Technology [Wuhan] (HUST), Barcelona Supercomputing Center - Centro Nacional de Supercomputacion (BSC - CNS), Purdue University [West Lafayette], Kitasato University, Stony Brook University [SUNY] (SBU), State University of New York (SUNY), Department of Biomedical Engineering [Boston], Boston University [Boston] (BU), Computational Algorithms for Protein Structures and Interactions (CAPSID), Inria Nancy - Grand Est, Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Department of Complex Systems, Artificial Intelligence & Robotics (LORIA - AIS), Laboratoire Lorrain de Recherche en Informatique et ses Applications (LORIA), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Lorrain de Recherche en Informatique et ses Applications (LORIA), Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Institut National de Recherche en Informatique et en Automatique (Inria)-Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL), Technische Universität Munchen - Université Technique de Munich [Munich, Allemagne] (TUM), King Abdullah University of Science and Technology (KAUST), University of Naples Federico II, Service des Recherches Métallurgiques Appliquées (SRMA), Département des Matériaux pour le Nucléaire (DMN), CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire) (CEA-DES (ex-DEN)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Department of Chemistry, Seoul National University [Seoul] (SNU), The Hebrew University of Jerusalem (HUJ), Vilnius University [Vilnius], Department of Molecular Biosciences [Lawrence], University of Kansas [Lawrence] (KU), University of Kansas [Kansas City], University of Massachusetts Medical School [Worcester] (UMASS), University of Massachusetts System (UMASS), Program in Bioinformatics and Integrative Biology [Worcester], University of Massachusetts System (UMASS)-University of Massachusetts System (UMASS), University of Maryland [Baltimore], Beijing University of Technology, University of Missouri [Columbia] (Mizzou), University of Missouri System, Bijvoet Center for Biomolecular Research [Utrecht], Utrecht University [Utrecht], Dalton Cardiovascular Research Center [Columbia], University of Missouri System-University of Missouri System, Shandong University, Laboratoire d'Informatique pour la Mécanique et les Sciences de l'Ingénieur (LIMSI), Université Paris-Sud - Paris 11 (UP11)-Sorbonne Université - UFR d'Ingénierie (UFR 919), Sorbonne Université (SU)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Saclay (COmUE), University of California [Santa Cruz] (UCSC), University of California, The Hospital for sick children [Toronto] (SickKids), Unité de Glycobiologie Structurale et Fonctionnelle - UMR 8576 (UGSF), Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Institut des Hautes Etudes Scientifiques (IHES), IHES, The Francis Crick Institute, Institut de Biologie Paris Seine (IBPS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria)-Laboratoire Jean Kuntzmann (LJK), Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Pierre Mendès France - Grenoble 2 (UPMF)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Polytechnique de Grenoble - Grenoble Institute of Technology-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut National Polytechnique de Grenoble (INPG), Weizmann Institute of Science, University of Gdańsk, Department of Environmental Analytics [Gdańsk], Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Laboratoire Lorrain de Recherche en Informatique et ses Applications (LORIA), Institut National de Recherche en Informatique et en Automatique (Inria)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Technische Universität München [München] (TUM), CEA-Direction de l'Energie Nucléaire (CEA-DEN), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-CEA-Direction de l'Energie Nucléaire (CEA-DEN), University of Missouri [Columbia], Université Paris-Sud - Paris 11 (UP11)-Université Paris-Saclay-Sorbonne Université - UFR d'Ingénierie (UFR 919), Sorbonne Université (SU)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Saclay (COmUE), Université de Lille, CNRS, Unité de Glycobiologie Structurale et Fonctionnelle UMR 8576 [UGSF], Agence Nationale de la Recherche (France), Cancer Research UK, European Commission, Medical Research Council (UK), National Institutes of Health (US), National Natural Science Foundation of China, National Research Foundation of Korea, National Science Foundation (US), Ministerio de Economía y Competitividad (España), Università degli Studi di Napoli PARTHENOPE, Wellcome Trust, Université de Lille-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Algorithms for Modeling and Simulating Nanosystems [2018-...] (NANO-D-POST [2018-2020]), Institut National de Recherche en Informatique et en Automatique (Inria)-Institut National de Recherche en Informatique et en Automatique (Inria), Department of Computer Science [Univ California Davis] (CS - UC Davis), University of California (UC)-University of California (UC), University of Naples Federico II = Università degli studi di Napoli Federico II, University of California [Santa Cruz] (UC Santa Cruz), University of California (UC), and Grudinin, Sergei

Subjects
Models, Molecular, Computer science, Protein Conformation, Protein complexes, Template‐based modeling, Oligomeric state, Biochemistry, Docking, protein-protein interaction, Structural Biology, Protein Interaction Mapping, Taverne, Blind prediction, Protein assemblies, Databases, Protein, [INFO.INFO-BI] Computer Science [cs]/Bioinformatics [q-bio.QM], 0303 health sciences, oligomeric state, 030302 biochemistry & molecular biology, protein assemblies, computer.file_format, 3. Good health, CASP, docking, blind prediction, Protein‐protein interaction, CAPRI, proteincomplexes, Algorithms, Protein Binding, protein complexes, template-based modeling, Computational biology, Article, Protein–protein interaction, 03 medical and health sciences, protein‐protein interaction, template‐based modeling, Molecular Biology, 030304 developmental biology, Binding Sites, Computational Biology, Proteins, Protein Data Bank, Docking (molecular), Structural Homology, Protein, [INFO.INFO-BI]Computer Science [cs]/Bioinformatics [q-bio.QM], computer, Software
Abstract

We present the results for CAPRI Round 46, the third joint CASP‐CAPRI protein assembly prediction challenge. The Round comprised a total of 20 targets including 14 homo‐oligomers and 6 heterocomplexes. Eight of the homo‐oligomer targets and one heterodimer comprised proteins that could be readily modeled using templates from the Protein Data Bank, often available for the full assembly. The remaining 11 targets comprised 5 homodimers, 3 heterodimers, and two higher‐order assemblies. These were more difficult to model, as their prediction mainly involved “ab‐initio” docking of subunit models derived from distantly related templates. A total of ~30 CAPRI groups, including 9 automatic servers, submitted on average ~2000 models per target. About 17 groups participated in the CAPRI scoring rounds, offered for most targets, submitting ~170 models per target. The prediction performance, measured by the fraction of models of acceptable quality or higher submitted across all predictors groups, was very good to excellent for the nine easy targets. Poorer performance was achieved by predictors for the 11 difficult targets, with medium and high quality models submitted for only 3 of these targets. A similar performance “gap” was displayed by scorer groups, highlighting yet again the unmet challenge of modeling the conformational changes of the protein components that occur upon binding or that must be accounted for in template‐based modeling. Our analysis also indicates that residues in binding interfaces were less well predicted in this set of targets than in previous Rounds, providing useful insights for directions of future improvements., Agence Nationale de la Recherche, Grant/Award Number: ANR‐15‐CE11‐0029‐03; Cancer Research UK, Grant/Award Number: FC001003; H2020 European Institute of Innovation and Technology, Grant/Award Numbers: 675728, 777536, 823830; Lietuvos Mokslo Taryba, Grant/Award Number: S‐MIP‐17‐60; Medical Research Council, Grant/Award Number: FC001003; National Institutes of Health, Grant/Award Numbers: R01GM074255, R01GM123055, R35GM124952; National Natural Science Foundation of China, Grant/Award Number: 31670724; National Research Foundation of Korea, Grant/Award Number: 2016M3C4A7952630; National Science Foundation, Grant/Award Number: DBI1565107; Nederlandse Organisatie voor Wetenschappelijk Onderzoek, Grant/Award Number: 718.015.001; Spanish >Programma Estatal I+D+i>, Grant/Award Number: BIO2016‐79930‐R; University Parthenope, Grant/Award Number: Finanziamento per il Sostegno alla Ricerca Individ; Wellcome Trust, Grant/Award Number: FC001003

Published
2019

12. Correlation of optical and structural properties of GaN/AlN multi-quantum wells— Ab initio and experimental study

Author

Ewa Grzanka, Kamil Sobczak, Pawel Strak, M. Beeler, Agata Kaminska, Konrad Sakowski, Jolanta Borysiuk, J. Z. Domagala, Eva Monroy, Stanisław Krukowski, Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Institute of High Pressure Physics [Warsaw] (IHPP), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Nanophysique et Semiconducteurs (NPSC), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
Photoluminescence, Materials science, Ab initio, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, Condensed Matter::Materials Science, symbols.namesake, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Ab initio quantum chemistry methods, 0103 physical sciences, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, Quantum well, ComputingMilieux_MISCELLANEOUS, Wurtzite crystal structure, 010302 applied physics, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Condensed matter physics, Wide-bandgap semiconductor, 021001 nanoscience & nanotechnology, Stark effect, symbols, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, 0210 nano-technology, Molecular beam epitaxy
Abstract

The results of comprehensive theoretical and experimental study of binary GaN/AlN multi-quantum well (MQW) systems oriented along polar c-direction of their wurtzite structure are presented. A series of structures with quantum wells and barriers of various thicknesses were grown by plasma-assisted molecular-beam epitaxy and characterized by x-ray diffraction and transmission electron microscopy. It was shown that in general the structures of good quality were obtained, with the defect density decreasing with increasing quantum well thickness. The optical transition energies in these structures were investigated comparing experimental measurements with ab initio calculations of the entire GaN/AlN MQW structure depending on the QW widths and strains, allowing for direct determination of the energies of optical transitions and the electric fields in wells/barriers by electric potential double averaging procedure. Photoluminescence (PL) measurements revealed that the emission efficiency as well as the shape o...

Published
2016

13. Amyloid beta Protein and Alzheimer\textquoterights Disease: When Computer Simulations Complement Experimental Studies

Author

Nasica-Labouze, Jessica, Nguyen, Phuong H., Sterpone, Fabio, Berthoumieu, Olivia, Buchete, Nicolae-Viorel, Cote, Sebastien, De Simone, Alfonso, Doig, Andrew J., Faller, Peter, Garcia, Angel, Laio, Alessandro, Li, Mai Suan, Melchionna, Simone, Mousseau, Normand, Mu, Yuguang, Paravastu, Anant, Pasquali, Samuela, Rosenman, David J., Strodel, Birgit, Tarus, Bogdan, Viles, John H., ZHANG, Tong, Wang, Chunyu, Derreumaux, Philippe, Laboratoire de biochimie théorique [Paris] (LBT (UPR_9080)), Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut de biologie physico-chimique (IBPC (FR_550)), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institut de Biologie Physico-Chimique (Centre National de la Recherche Scientifique UPR 1929), Université Paris Diderot - Paris 7 (UPD7), Laboratoire de chimie de coordination (LCC), Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie de Toulouse (ICT-FR 2599), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Complex & Adaptive Systems Laboratory - University College Dublin (CASL), University College Dublin [Dublin] (UCD), Département de Physique [Montréal], Université de Montréal (UdeM), Department of Life Sciences, Imperial College London, University of Manchester [Manchester], Rensselaer Polytechnic Institute (RPI), Scuola Internazionale Superiore di Studi Avanzati / International School for Advanced Studies (SISSA / ISAS), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Instituto per i Processi Chimico-Fisici [Roma] (IPCF), Consiglio Nazionale delle Ricerche [Roma] (CNR), School of Biological sciences, Nanyang Technological University [Singapour], Florida State University [Tallahassee] (FSU), National High Magnetic Field Laboratory, University of Florida [Gainesville] (UF), Heinrich Heine Universität Düsseldorf = Heinrich Heine University [Düsseldorf], Forschungszentrum Jülich GmbH | Centre de recherche de Juliers, Helmholtz-Gemeinschaft = Helmholtz Association, Unité de recherche Virologie et Immunologie Moléculaires (VIM (UR 0892)), Institut National de la Recherche Agronomique (INRA), School of Biological and Chemical Sciences [London], Queen Mary University of London (QMUL), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Centre National de la Recherche Scientifique (CNRS)-Institut de biologie physico-chimique (IBPC), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Montréal [Montréal], International School for Advanced Studies [Trieste, Italy] (SISSA), University of Florida [Gainesville], Heinrich-Heine-Universität Düsseldorf [Düsseldorf], Forschungszentrum Jülich GmbH, Unité de recherche Virologie et Immunologie Moléculaires (VIM), Université Paris Diderot - Paris 7 (UPD7)-Institut de biologie physico-chimique (IBPC), and Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDV.BBM.BP]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Biophysics, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; no abstract

Published
2015

14. Magnetoplasmons in high electron mobility CdTe/CdMgTe quantum wells

Author

G. Karczewski, Tomasz Wojtowicz, Jerzy Łusakowski, Jerzy Wróbel, I. Grigelionis, H. Mariette, M. Czapkiewicz, H. Boukari, K. Nogajewski, Laboratoire national des champs magnétiques intenses - Grenoble (LNCMI-G), Université Joseph Fourier - Grenoble 1 (UJF)-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), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institute of Physics, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Structure des interfaces et fonctionnalités des couches minces (SIFCOM), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Nanophysique et Semiconducteurs (NPSC), Institut Néel (NEEL), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Centre National de la Recherche Scientifique (CNRS)-École Nationale Supérieure d'Ingénieurs de Caen (ENSICAEN), Normandie Université (NU)-Normandie Université (NU)-Université de Caen Normandie (UNICAEN), and Normandie Université (NU)

Subjects
Physics, [PHYS]Physics [physics], Condensed matter physics, Phonon, Quantum point contact, Cyclotron resonance, Physics::Optics, 02 engineering and technology, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Polaron, 7. Clean energy, 01 natural sciences, Electronic, Optical and Magnetic Materials, Excited state, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], 0103 physical sciences, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, Fermi gas, Plasmon, Quantum well, ComputingMilieux_MISCELLANEOUS
Abstract

Terahertz magnetospectroscopy experiments on high quality CdTe/CdMgTe quantum wells were carried out at low temperatures and high magnetic fields. Samples of two different geometries were considered: a large-area grid-gated sample and a split-gate quantum point contact (QPC). The spectra show features originating from a cyclotron resonance transition and magnetoplasmon excitations. Depending on the sample geometry, plasmons characterized by an effective dielectric function of a mixed gated/ungated (in grid-gated samples) or ungated type (in the QPC) were excited. In each case, the resulting plasmon dispersion relation was determined and we show that it can be precisely described within a theory based on a local approximation of a high-frequency magnetoconductivity tensor of a two-dimensional electron gas by taking into account a polaron effect and plasmon-longitudinal optical (LO) phonon interaction.

Published
2015

15. Electron density magnification of the collective spin-orbit field in quantum wells

Author

G. Karczewski, Florent Perez, F. Baboux, Tomasz Wojtowicz, Carsten A. Ullrich, Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Nanostructures et systèmes quantiques (INSP-E1), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [Columbia] (Mizzou Physics), University of Missouri [Columbia] (Mizzou), University of Missouri System-University of Missouri System, Institute of Physics [Warsaw] (IFPAN), and Polish Academy of Sciences (PAN)

Subjects
Physics, Coupling constant, Electron density, Condensed matter physics, Field (physics), 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 01 natural sciences, Electronic, Optical and Magnetic Materials, Spin wave, 0103 physical sciences, Condensed Matter::Strongly Correlated Electrons, Atomic physics, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], 010306 general physics, 0210 nano-technology, Fermi gas, Quantum well, Spin-½, Electronic density
Abstract

International audience; The spin-orbit field acting on the spin waves of a spin-polarized electron gas is studied by in-elastic light scattering on a CdMnTe quantum well. Above-barrier illumination allows us to vary the electronic density and control the collective Rashba and Dresselhaus coupling constants. We demonstrate that the enhancement between the single-particle and the collective spin-orbit field increases with increasing electronic density. This result is reproduced by a first-principles calculation. This behavior, which is opposite to usual Coulombic spin enhancements, reveals a novel aspect of the interplay of spin-orbit and Coulomb interactions in collective spin modes.

Published
2015

16. Ferromagnetic resonance in Mn5Ge3 epitaxial films with weak stripe domain structure

Author

Waldemar Bednarski, Lisa Michez, Pavlo Aleshkevych, Matthieu Petit, Marek Wojcik, E. Jedryka, R. Kalvig, Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Institute of Molecular Physics, Polska Akademia Nauk = Polish Academy of Sciences (PAN), Centre Interdisciplinaire de Nanoscience de Marseille (CINaM), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)

Subjects
Materials science, Acoustics and Ultrasonics, Magnetic domain, Film plane, Mn5Ge3, Context (language use), 02 engineering and technology, 01 natural sciences, Condensed Matter::Materials Science, Magnetization, stripe domain structure, 0103 physical sciences, 010306 general physics, Anisotropy, Condensed matter physics, Condensed Matter::Other, FMR, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Ferromagnetic resonance, uniaxial anisotropy, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Magnetic field, Hysteresis, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology
Abstract

International audience; Extensive X-band and Q-band FMR experiments have been performed in the Mn5Ge3 epitaxial films with thicknesses varying between 4.5 and 68 nm. FMR signals were recorded in the temperature range between 15 and 295 K, at different orientations of magnetic field with respect to the film plane. In addition to the acoustic FMR mode with well defined resonance field, originating from inside the magnetic domains, a broad absorption line has been observed at low fields and attributed to the unresolved spectrum of FMR modes having the origin in flux closure caps. The FMR results have been discussed in the context of the domain structure computed with the use of OOMMF micromagnetic calculations and giving good agreement with the experimental hysteresis curves. From the Q-band experiments, where the FMR signal is observed in the magnetically saturated sample, the uniaxial anisotropy constant in films with different thicknesses has been determined as a function of temperature. This FMR study provides the evidence that the strong uniaxial anisotropy observed in epitaxial thin films of Mn5Ge3 leads to the formation of a stripe domain structure above 25 nm, in agreement with the published reports on magnetization studies in these films. It also eliminates a possible confusion that may arise from previously published FMR studies on films grown with the same method, which led their authors to conclude that the shape anisotropy can force the magnetization to the in-plane orientation in this thickness range and even above it.

Published
2017

17. Plasmonic terahertz detectors based on a high-electron mobility GaAs/AlGaAs heterostructure

Author

M. Grynberg, Milan Orlita, Jerzy Wróbel, Vladimir Umansky, M. Białek, A. M. Witowski, M. Czapkiewicz, J. Łusakowski, Marek Potemski, Faculty of Physics [Warsaw] (FUW), University of Warsaw (UW), Laboratoire national des champs magnétiques intenses - Grenoble (LNCMI-G), Université Joseph Fourier - Grenoble 1 (UJF)-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), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Faculty of Mathematics and Applied Physics [Rzeszow], Rzeszow University of Technology, Weizmann Institute of Science [Rehovot, Israël], Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées

Subjects
Physics, [PHYS]Physics [physics], Electron mobility, Condensed Matter - Materials Science, Photon, Spectrometer, Condensed Matter - Mesoscale and Nanoscale Physics, Terahertz radiation, business.industry, Cyclotron resonance, Materials Science (cond-mat.mtrl-sci), FOS: Physical sciences, General Physics and Astronomy, Physics::Optics, Electron, Laser, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, law.invention, law, Mesoscale and Nanoscale Physics (cond-mat.mes-hall), Optoelectronics, [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], business, Plasmon, ComputingMilieux_MISCELLANEOUS
Abstract

In order to characterize magnetic-field (B) tunable THz plasmonic detectors, spectroscopy experiments were carried out at liquid helium temperatures and high magnetic fields on devices fabricated on a high electron mobility GaAs/AlGaAs heterostructure. The samples were either gated (the gate of a meander shape) or ungated. Spectra of a photovoltage generated by THz radiation were obtained as a function of B at a fixed THz excitation from a THz laser or as a function of THz photon frequency at a fixed B with a Fourier spectrometer. In the first type of measurements, the wave vector of magnetoplasmons excited was defined by geometrical features of samples. It was also found that the magnetoplasmon spectrum depended on the gate geometry which gives an additional parameter to control plasma excitations in THz detectors. Fourier spectra showed a strong dependence of the cyclotron resonance amplitude on the conduction-band electron filling factor which was explained within a model of the electron gas heating with the THz radiation. The study allows to define both the advantages and limitations of plasmonic devices based on high-mobility GaAs/AlGaAs heterostructures for THz detection at low temperatures and high magnetic fields., 8 pages, 11 figures

Published
2014

18. Granular Fe 3 − x O 4 -CoO hetero-nanostructures produced by in situ seed mediated growth in polyol: magnetic properties and chemical stability

Author

Souad Ammar, Jean-Marc Greneche, Nader Yaacoub, Nicolas Menguy, M Galmiche, A. Slawska-Waniewska, N. Nedelko, Fayna Mammeri, R. Sayed Hassan, Thomas Gaudisson, Institut des Molécules et Matériaux du Mans (IMMM), Le Mans Université (UM)-Centre National de la Recherche Scientifique (CNRS), Interfaces, Traitements, Organisation et Dynamique des Systèmes (ITODYS (UMR_7086)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7), Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Le Mans Université (UM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Université Paris Diderot - Paris 7 (UPD7)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), and Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], Materials science, Polymers and Plastics, Magnetism, Metals and Alloys, Iron oxide, chemistry.chemical_element, Nanotechnology, Coercivity, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Biomaterials, chemistry.chemical_compound, Magnetization, chemistry, Chemical engineering, Ferrimagnetism, Ferrite (magnet), [PHYS.COND]Physics [physics]/Condensed Matter [cond-mat], Cobalt, Iron oxide nanoparticles, ComputingMilieux_MISCELLANEOUS
Abstract

We report here the synthesis of granular composites based on intimately mixed ferrimagnetic Fe3 − x O4 and antiferromagnetic CoO nanocrystals using forced hydrolysis in a polyol solvent. Typically, 10 nm sized iron oxide nanoparticles were pre-formed in diethyleneglycol and used as seeds to grow epitaxially cobalt monoxide nanocrystals, in the same reaction mixture. X-ray diffraction, transmission electron microscopy, 57Fe Mossbauer spectrometry and dc-magnetometry confirmed the production of the desired hetero-nanostructures, of great interest in the field of magnetic recording, and evidenced the formation of a kind of cobalt ferrite solid solution between the initially formed Fe3 − x O4 and latterly deposited CoO nanocrystals. The resulting Co and Fe concentration gradient significantly affects the low temperature magnetization reversal of the composite nanostructures compared to the pristine iron oxide magnetite-like powder. Moreover, with time, air exposure leads to an almost total transformation of the CoO phase into Co3O4 and the electronic displacement of a great part of the Fe2+ ions into Fe3+ ones in the whole grain volume, along with noteworthy low temperature magnetization and coercivity decrease. This material evolution makes the studied composites less valuable for most of the magnetic based functional applications and underlines the importance to pay attention to their storage and integration into functional devices before use.

Published
2014

19. Designing an assistive robot for older adults: the Robadom project

Author

Victoria Cristancho-Lacroix, Dominique Duhaut, L. Kamali, M. Ghrissi, Anne-Sophie Rigaud, Céline Jost, B. Le Pevedic, Mohamed Chetouani, V. Dupourque, Jérémy Wrobel, Y.-H. Wu, AP-HP - Hôpital Cochin Broca Hôtel Dieu [Paris], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Institut des Systèmes Intelligents et de Robotique (ISIR), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Lab-STICC_UBS_CID_IHSEV, Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), robosoft, Société, Le Pévédic, Brigitte, Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Robosoft [Bidart], Robosoft, EHT0202/002 study group, and ExonHit Therapeutics SA

Subjects
Engineering, business.product_category, 020205 medical informatics, media_common.quotation_subject, Population, Biomedical Engineering, Biophysics, [SCCO.COMP]Cognitive science/Computer science, 02 engineering and technology, [INFO.INFO-AI]Computer Science [cs]/Artificial Intelligence [cs.AI], 03 medical and health sciences, 0302 clinical medicine, [INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing, Human–computer interaction, Perception, 0202 electrical engineering, electronic engineering, information engineering, [INFO.INFO-RB]Computer Science [cs]/Robotics [cs.RO], [INFO.INFO-HC]Computer Science [cs]/Human-Computer Interaction [cs.HC], education, ComputingMilieux_MISCELLANEOUS, media_common, education.field_of_study, Social robot, [SDV.MHEP.GEG] Life Sciences [q-bio]/Human health and pathology/Geriatry and gerontology, business.industry, [SCCO.NEUR]Cognitive science/Neuroscience, [SDV.MHEP.GEG]Life Sciences [q-bio]/Human health and pathology/Geriatry and gerontology, technology, industry, and agriculture, [INFO.INFO-CV]Computer Science [cs]/Computer Vision and Pattern Recognition [cs.CV], Social environment, Object (philosophy), body regions, surgical procedures, operative, Laptop, [SCCO.PSYC]Cognitive science/Psychology, Assistive robot, Robot, [INFO.INFO-HC] Computer Science [cs]/Human-Computer Interaction [cs.HC], business, human activities, 030217 neurology & neurosurgery
Abstract

International audience; Objective. - The ROBADOM project was devoted to the design of a "robot butler", capable of providing verbal and non-verbal interactions and feedbacks for assisting older adults at home. In this article we focused on the following issues: (1) study the social context for designing social robot; define the robot appearance and investigate the perceptions and attitudes of older adults towards an assistive robot; (2) examine the perception of the expressivity of the robot, the social signals showing the end-user engagement level and the role of agent embodiment during the interaction between older adults and a robot. Method. - The design of the studies involved both qualitative and experimental methods. Results & Discussion. - Small robots with some traits between human/animal and machine were appreciated by the participants. As regards services, cognitive stimulation, reminder and object localization were positively rated. Although the participants considered an assistive robot as useful, they were not yet ready to adopt it. The expressions of the robot were perceived differently in older and young adults. Thus, a robotic system dedicated to older adults should be tailored to the specific characteristics of this population. We also identified social signals as indicators of the user's engagement level during interaction. Finally, the issue of the added valued of a robotic system in comparison to a laptop was raised by our participants. Therefore, various issues (technological development, human-robot interaction, social context. . .) are to be explored before testing the impact of the robot at home.

Published
2013

20. Near-forward Raman scattering by bulk and surface phonon-polaritons in the model percolation-type ZnBeSe alloy

Author

R. Hajj Hussein, Franciszek Firszt, Alain Maillard, Olivier Pagès, Wojciech Paszkowicz, Laboratoire de Chimie et Physique - Approche Multi-échelle des Milieux Complexes (LCP-A2MC), Université de Lorraine (UL), Institute of Physics, Nicolaus Copernicus University [Toruń], Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Laboratoire Matériaux Optiques, Photonique et Systèmes (LMOPS), and CentraleSupélec-Université de Lorraine (UL)

Subjects
Materials science, Physics and Astronomy (miscellaneous), Alloy, FOS: Physical sciences, 02 engineering and technology, engineering.material, 01 natural sciences, symbols.namesake, Condensed Matter::Materials Science, 0103 physical sciences, Polariton, 010306 general physics, Condensed Matter - Materials Science, Condensed matter physics, Wide-bandgap semiconductor, Materials Science (cond-mat.mtrl-sci), Surface phonon, ZnBeSe, 021001 nanoscience & nanotechnology, Dielectric response, Formalism (philosophy of mathematics), Raman Scattering, symbols, engineering, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], 0210 nano-technology, Raman spectroscopy, Raman scattering
Abstract

International audience; We study the bulk and surface phonon-polaritons of the Zn0.67Be0.33Se zincblende alloy by near-forward Raman scattering. The short (Be-Se) bond exhibits a distinct percolation doublet in the conventional backscattering Raman spectra, corresponding to a three-mode behavior in total [1××(Zn-Se), 2××(Be-Se)] for Zn0.67Be0.33Se. This offers an opportunity to achieve a refined understanding of the phonon-polariton modes of a zincblende alloy beyond the current two-mode approximation, corresponding to a [1××(Zn-Se), 1××(Be-Se)] description in the present case. The discussion is supported by contour modeling of the Raman signals of the multi-mode bulk and surface phonon-polaritons within the formalism of the linear dielectric response.

Published
2013
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21. Terahertz Response of a Point Contact Based on CdTe/CdMgTe Quantum Well in Magnetic Field

Author

Jerzy Łusakowski, M. Grynberg, M. Czapkiewicz, V. Kolkovskiy, Wojciech Knap, Jerzy Wróbel, I. Grigelionis, Tomasz Wojciechowski, Maciej Wiater, M. Białek, Tomasz Wojtowicz, Dmytro B. But, Institute of Experimental Physics [Warsaw] (IFD), Faculty of Physics [Warsaw] (FUW), University of Warsaw (UW)-University of Warsaw (UW), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Laboratoire Charles Coulomb (L2C), and Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Condensed matter physics, Terahertz radiation, business.industry, General Physics and Astronomy, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 7. Clean energy, 01 natural sciences, Cadmium telluride photovoltaics, [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph], Magnetic field, Point contact, 0103 physical sciences, Optoelectronics, 010306 general physics, 0210 nano-technology, business, Quantum well
Abstract

A photoresponse at THz frequencies of a quantum point contact fabricated on a CdTe/CdMgTe quantum well was studied at low temperatures as a function of magnetic field. The spectra show a structure which was interpreted as resulting from the cyclotron resonance and magnetoplasmon excitations. The wavelength of the fundamental magnetoplasmon mode was found to be about 2 mu m which coincides with one of dimensions of the point contact. We also discuss the possibility of coupling of magnetoplasmon modes to shallow impurity transitions in the quantum well.

Published
2012

22. High pressure and time resolved studies of optical properties of n-type doped GaN/AlN multi-quantum wells: Experimental and theoretical analysis

Author

Ewa Grzanka, Jolanta Borysiuk, Agata Kaminska, Kamil Sobczak, Pawel Strak, M. Beeler, Eva Monroy, Konrad Sakowski, Krzysztof P. Korona, Dawid Jankowski, Stanisław Krukowski, Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Nanophysique et Semiconducteurs (NPSC), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institute of High Pressure Physics [Warsaw] (IHPP), and Polska Akademia Nauk = Polish Academy of Sciences (PAN)

Subjects
010302 applied physics, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Photoluminescence, Materials science, Condensed matter physics, Band gap, Oscillator strength, Wide-bandgap semiconductor, General Physics and Astronomy, 02 engineering and technology, 021001 nanoscience & nanotechnology, 01 natural sciences, Condensed Matter::Materials Science, [PHYS.QPHY]Physics [physics]/Quantum Physics [quant-ph], Quantum dot, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Density of states, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 0210 nano-technology, Electronic band structure, ComputingMilieux_MISCELLANEOUS, Quantum well
Abstract

High-pressure and time-resolved studies of the optical emission from n-type doped GaN/AlN multi-quantum-wells (MQWs) with various well thicknesses are analysed in comparison with ab initio calculations of the electronic (band structure, density of states) and optical (emission energies and their pressure derivatives, oscillator strength) properties. The optical properties of GaN/AlN MQWs are strongly affected by quantum confinement and polarization-induced electric fields. Thus, the photoluminescence (PL) peak energy decreases by over 1 eV with quantum well (QW) thicknesses increasing from 1 to 6 nm. Furthermore, the respective PL decay times increased from about 1 ns up to 10 μs, due to the strong built-in electric field. It was also shown that the band gap pressure coefficients are significantly reduced in MQWs as compared to bulk AlN and GaN crystals. Such coefficients are strongly dependent on the geometric factors such as the thickness of the wells and barriers. The transition energies, their oscilla...

Published
2016

23. Thermal annealing of molecular beam epitaxy-grown InGaN/GaN single quantum well

Author

Sławomir Kret, F. Ivaldi, Denis Martin, Nils. A. K. Kaufmann, Pierre Valvin, Amélie Dussaigne, Nicolas Grandjean, Thierry Guillet, Bernard Gil, Institute of Condensed Matter Physics [Lausanne], Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics [Warsaw] (IFPAN), and Polish Academy of Sciences (PAN)

Subjects
010302 applied physics, Materials science, Photoluminescence, Annealing (metallurgy), business.industry, Quantum point contact, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Crystallographic defect, Electronic, Optical and Magnetic Materials, Quantum dot, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], 0103 physical sciences, Materials Chemistry, Optoelectronics, Quantum efficiency, Electrical and Electronic Engineering, 0210 nano-technology, business, Quantum well, Molecular beam epitaxy
Abstract

International audience; The effect of thermal annealing on In0.25Ga0.75N/GaN quantum wells grown by molecular beam epitaxy at 550°C is investigated. A strong increase in the 300 K photoluminescence (PL) intensity is observed for samples annealed at 880°C, while degradation occurs for higher temperatures. The improvement of the optical properties is ascribed to higher internal quantum efficiency (IQE), as indicated by temperature-dependent and time-resolved PL experiments. The effect of carrier localization due to possible quantum dot formation via indium clustering is ruled out based on high-resolution transmission electron microscopy imaging. IQE improvement is thus attributed to a reduction of point defects upon annealing.

Published
2012

24. Anomalously large spin susceptibility enhancement in n-doped CdMnTe quantum wells

Author

Z. Ben Cheikh, G. Karczewski, Tomasz Wojtowicz, Florent Perez, Steeve Cronenberger, M. Vladimirova, K. Boujdaria, Denis Scalbert, F. Baboux, Physique de l'Exciton, du Photon et du Spin (PEPS), Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut des Nanosciences de Paris (INSP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics [Warsaw] (IFPAN), and Polish Academy of Sciences (PAN)

Subjects
Physics, Condensed matter physics, Spin polarization, Spin wave, [PHYS.COND.CM-GEN]Physics [physics]/Condensed Matter [cond-mat]/Other [cond-mat.other], Spinplasmonics, Condensed Matter::Strongly Correlated Electrons, Electron, Spin-flip, Fermi gas, Spin (physics), Quantum well
Abstract

We report on time-resolved Kerr rotation (TRKR) experiments done on n-doped CdMnTe quantum wells (QWs), in the regime where strong coupling between the electron and the Mn spin-flip excitations shows up. It has been proposed previously to deduce the 2D electron gas spin susceptibility from the coupling energy between these spin excitations. Here we measure the coupling energy on a high mobility sample down to very low excitation density, and compare the results with spin-flip Raman scattering (SFRS) on the same sample. The electron spin polarizations measured by TRKR and SFRS are found in relatively good agreement. However the spin susceptibility measured by TRKR exceeds systematically the values predicted by many-body theory. This could be an indication that the two-oscillator model used to describe mixed electron-Mn spin excitations needs to be improved.

Published
2012

25. Magnetospectroscopy of two-dimensional HgTe-based topological insulators around the critical thickness

Author

G. Grabecki, Jérémi Torres, Vladimir Ya. Aleshkin, Nikolay N. Mikhailov, Jerzy Wróbel, K. E. Spirin, M. S. Zholudev, Wojciech Knap, Milan Orlita, M. Czapkiewicz, S. A. Dvoretskii, C. Consejo, Vladimir I. Gavrilenko, Nina Dyakonova, A. V. Ikonnikov, Frederic Teppe, Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire national des champs magnétiques intenses - Grenoble (LNCMI-G), Université Joseph Fourier - Grenoble 1 (UJF)-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), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Institut d’Electronique et des Systèmes (IES), Térahertz, hyperfréquence et optique (TéHO), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Rzhanov Institute of Semiconductor Physics (ISP), Siberian Branch of the Russian Academy of Sciences (SB RAS), Institute for Physics of Microstructures of the RAS, Russian Academy of Sciences [Moscow] (RAS), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées

Subjects
010302 applied physics, Physics, Valence (chemistry), Condensed matter physics, Avoided crossing, Terahertz, Landau quantization, Condensed Matter Physics, 01 natural sciences, Electronic, Optical and Magnetic Materials, symbols.namesake, Topological Insulator, Dirac fermion, Magnetospectroscpopy, Topological insulator, 0103 physical sciences, symbols, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], HgTe QWs, 010306 general physics, Electronic band structure, Quantum well, Energy (signal processing)
Abstract

Recently, a new class of materials, so-called topological insulators, has emerged. These are systems characterized by the inversion of the electronic band structure and also by a certain strength of the spin-orbit interaction. HgTe/Cd${}_{x}$Hg${}_{1\ensuremath{-}x}$Te quantum wells represent a prominent example. They can change to the topological insulator phase from the conventional insulator phase when the thickness of the quantum well is increased over the critical thickness ${d}_{c}$ = 6.3 nm. Here, we report on a far-infrared magnetospectroscopy study of a set of HgTe/Cd${}_{x}$Hg${}_{1\ensuremath{-}x}$Te quantum wells with different thicknesses from below to above the critical value ${d}_{c}$. In quantizing magnetic fields up to 16 T, both intraband and interband transitions have been clearly observed. In the widest quantum well with inverted band structure, we confirm the avoided crossing of the zero-mode Landau levels observed earlier in similar structures. In both noninverted quantum wells close to the critical thickness, we report unambiguously on the square root dependence of the transition energy on the magnetic field, as expected in the single-particle model of massless Dirac fermions. The obtained results are compared with the allowed transition energies between Landau levels in the valence and conduction bands calculated using the 8 \ifmmode\times\else\texttimes\fi{} 8 Kane model.

Published
2012

26. Magnetospectroscopy of 2D HgTe Based Topological Insulators

Author

S. A. Dvoretskii, M. Czapkiewicz, M. S. Zholudev, Milan Orlita, Frederic Teppe, Vladimir Ya. Aleshkin, Jeremie Torres, Jerzy Wróbel, C. Consejo, Wojciech Knap, V. I. Gavrilenko, N. N. Mikhailov, G. Grabecki, Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institute for Physics of Microstructures of the RAS, Russian Academy of Sciences [Moscow] (RAS), Laboratoire national des champs magnétiques intenses - Grenoble (LNCMI-G), Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-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), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Rzhanov Institute of Semiconductor Physics (ISP), Siberian Branch of the Russian Academy of Sciences (SB RAS), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Condensed matter physics, Terahertz radiation, Condensed Matter::Other, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 01 natural sciences, 010305 fluids & plasmas, Magnetic field, Hall effect, Topological insulator, 0103 physical sciences, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Semiconductor quantum wells, 010306 general physics, Quantum well
Abstract

We report on a magnetospectroscopy study of a set of four HgTe quantum wells of different thickness. In quantizing magnetic fields, intraband and interband transitions have been observed. The obtained results are compared with the allowed transition energies calculated using the 8 × 8 Kane model.

Published
2012

27. Surprisingly low built-in electric fields in quaternary InAlGaN heterostructures

Author

L. H. Dmowski, Leszek Konczewicz, Agata Kaminska, Hideki Hirayama, Pierre Lefebvre, S. P. Łepkowski, Yoshinobu Aoyagi, Henryk Teisseyre, Stéphanie Anceau, Tadeusz Suski, Andrzej Suchocki, Groupe d'étude des semiconducteurs (GES), Centre National de la Recherche Scientifique (CNRS)-Université Montpellier 2 - Sciences et Techniques (UM2), Institute of High Pressure Physics [Warsaw] (IHPP), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), RIKEN - Institute of Physical and Chemical Research [Japon] (RIKEN), and European Materials Research Society

Subjects
010302 applied physics, [PHYS.PHYS.PHYS-OPTICS]Physics [physics]/Physics [physics]/Optics [physics.optics], Photoluminescence, Condensed matter physics, business.industry, Chemistry, Heterojunction, 02 engineering and technology, 021001 nanoscience & nanotechnology, Condensed Matter Physics, 01 natural sciences, Electronic, Optical and Magnetic Materials, Optics, Electrical transport, Light energy, Electric field, 0103 physical sciences, Unintentional doping, Magnitude (astronomy), [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, 0210 nano-technology, Luminescence, business
Abstract

International audience; Measurements of (i) the time-resolved photoluminescence and (ii) pressure dependence of the emitted light energy in two series of quaternary (AlInGa)N multiquantum wells have been used to point out the small magnitude of internal electric field as promoting highly efficient luminescence in these specially designed heterostructures. Findings of the experimental examination give the magnitude of built-in electric field few times smaller than that predicted theoretically. Electrical transport measurements support the explanation of the obtained results consisting of the screening of the built-in electric field by means of unintentional doping.

Published
2003

28. Spin Excitations of the Spin-Polarized Electron Gas in Semimagnetic Quantum Wells

Author

Christophe Testelin, Tomasz Wojtowicz, Grzegorz Karczewski, Florent Perez, Bernard Jusserand, Daniel Wolverson, David Richards, James Davies, Laboratoire de photonique et de nanostructures (LPN), Centre National de la Recherche Scientifique (CNRS), Dpt of Physics [London], King‘s College London-Department of Physics, King's College London, Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Groupe de Physique des Solides (GPS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Department of Physics [Bath], and University of Bath [Bath]

Subjects
Physics, [PHYS]Physics [physics], Zeeman effect, Spin polarization, Condensed matter physics, 72.25.Dc, 73.21.–b, 75.70.–i, 78.30.–j, General Physics and Astronomy, 02 engineering and technology, Zero field splitting, 021001 nanoscience & nanotechnology, 01 natural sciences, symbols.namesake, Spin wave, 0103 physical sciences, symbols, Wave vector, Zeeman energy, Atomic physics, 010306 general physics, 0210 nano-technology, Fermi gas, Spin-½
Abstract

International audience; Collective and single-particle spin-flip excitations of a two-dimensional electron gas in a semimagnetic Cd1–xMnxTe quantum well are observed by resonant Raman scattering. Application of a magnetic field splits the spin subbands and a spin polarization is induced in the electron gas. Above 1 T the collective modes, which disperse with the in-plane wave vector, dominate the spectra. The local spin-density approximation provides a good description of our results and enables us to confirm that the energy of the low wave vector collective mode is given by the bare Zeeman energy.

Published
2003

29. Magnons in layered MnTe/CdTe structures

Author

Grzegorz Karczewski, Michel Jouanne, J. M. Hartmann, Tomasz Wojtowicz, W. Szuszkiewicz, Henri Mariette, Elżbieta Dynowska, M.A. Kanehisa, Jacek Kossut, J.F. Morhange, J. Barnas, Laboratoire des Milieux Désordonnés et Hétérogènes (LMDH), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Nanophysique et Semiconducteurs (NPSC), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institute of Physics [Warsaw] (IFPAN), and Polish Academy of Sciences (PAN)

Subjects
[PHYS]Physics [physics], Condensed matter physics, Chemistry, Magnon, Magnetic semiconductor, Condensed Matter Physics, Cadmium telluride photovoltaics, Inorganic Chemistry, Condensed Matter::Materials Science, symbols.namesake, Spin wave, Materials Chemistry, symbols, Antiferromagnetism, Condensed Matter::Strongly Correlated Electrons, Thin film, Raman spectroscopy, Excitation
Abstract

An experimental and theoretical analysis of spin-wave excitations (magnons) in ultra-thin films of a magnetic semiconductor has been performed. Cubic MnTe, which possesses a frustrated long-range antiferromagnetic order when deposited in thick layers. was the material selected for such studies. In the low-frequency part of the Raman spectra. a complex structure has been observed in crossed polarization - z(x, y)z at low temperature on (MnTe) k /(CdTe) m , multilayers (where m ≥ 8). This structure can be attributed to magnons in thin MnTe slabs.

Published
1998

30. Raman Characterization of MBE-Grown Layered MnTe/CdTe Structures

Author

Elżbieta Dynowska, M. Jouanne, W. Szuszkiewicz, Jacek Kossut, Grzegorz Karczewski, Tomasz Wojtowicz, J. M. Hartmann, Henri Mariette, Józef Barnaś, M. A. Kanehisa, J.F. Morhange, Laboratoire des Milieux Désordonnés et Hétérogènes (LMDH), Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Spectrométrie Physique (LSP), Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Nanophysique et Semiconducteurs (NPSC), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institute of Physics [Warsaw] (IFPAN), and Polish Academy of Sciences (PAN)

Subjects
[PHYS]Physics [physics], symbols.namesake, Materials science, Raman scattering spectra, symbols, General Physics and Astronomy, Acoustic Phonons, Polarization (waves), Raman spectroscopy, Molecular physics, Raman scattering, Cadmium telluride photovoltaics
Abstract

Raman scattering measurements on (MnTe)8 /(Cd 0.64 Ζn 0.30Τc)8 multilayer grown by MBE method and on various (MnTe)n/(CdTe)ι2 multilayers (where n = 8,12,16, 24) were performed at low temperatures. In the z(x, x)z polarization, structures corresponding to folded acoustic phonons were found. In z(x, y)z polarization new complex structures were observed in the low-frequency part of Raman scattering spectra. A possible magnetic origin of these structures is discussed.

Published
1997

31. Temperature-Dependence of Exciton Radiative Recombination in (Al,Ga)N/GaN Quantum Wells Grown on a-Plane GaN Substrates

Author

Mehran Shahmohammadi, Jean-Daniel Ganière, Pierre Corfdir, Nicolas Grandjean, Henryk Teisseyre, Tadeusz Suski, Richard T. Phillips, Izabella Grzegory, Pierre Lefebvre, Benoit Deveaud, E. Giraud, Amélie Dussaigne, Institut de Physique de la Matière Condensée (EPFL), Ecole Polytechnique Fédérale de Lausanne (EPFL), Department of Physics, Cavendish Laboratory, University of Cambridge [UK] (CAM), Institute of High Pressure Physics [Warsaw] (IHPP), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Institute of Physics [Warsaw] (IFPAN), Polish Academy of Sciences (PAN), Laboratoire Charles Coulomb (L2C), Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Swiss National Science Foundation - Project No. 129715.Polish National Science Center (Project DEC-2011/03/B/ST3/02647)., European Project: 265073,EC:FP7:PEOPLE,FP7-PEOPLE-2010-ITN,NANOWIRING(2010), Phillips, Richard [0000-0002-8279-3475], and Apollo - University of Cambridge Repository

Subjects
radiative lifetime, Photoluminescence, quantum well, Exciton, General Physics and Astronomy, 02 engineering and technology, 01 natural sciences, GaN, Condensed Matter::Materials Science, 0103 physical sciences, Radiative transfer, Spontaneous emission, Biexciton, Quantum well, exciton, Condensed Matter::Quantum Gases, 010302 applied physics, Physics, Condensed matter physics, Condensed Matter::Other, General Engineering, PACS : 71.35.-y, 81.15.Hi, 81.07.St, 81.05.Ea, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Quantum efficiency, Charge carrier, 0210 nano-technology
Abstract

This article presents the dynamics of excitons in a-plane (Al,Ga)N/GaN single quantum wells of various thicknesses grown on bulk GaN substrates. For all quantum well samples, recombination is observed to be predominantly radiative in the low-temperature range. At higher temperatures, the escape of charge carriers from the quantum well to the (Al,Ga)N barriers is accompanied by a reduction in internal quantum efficiency. Based on the temperature-dependence of time-resolved photoluminescence experiments, we also show how the local disorder affects the exciton radiative lifetime at low temperature and the exciton non-radiative lifetime at high temperature.

Published
2013

32. Electrical Characterization of Delta Doped Gallium Arsenide

Author

Arscott, S., Missous, M., Dobaczewski, L., Harness, P., Maude, Duncan Kennedy, Portal, J., Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Institute of Physics [Warsaw] (IFPAN), and Polish Academy of Sciences (PAN)

Subjects
[SPI]Engineering Sciences [physics], AsGa, GaAs, Piège DX, DX centre
Abstract

International audience; Electrical Characterization of Delta Doped Gallium Arsenide; Caracterisation d'AsGa à plans de dopage

Published
1994

33. Observation of persistent photoconductivity in delta -doped GaAs

Author

L. Dobaczewski, Mohamed Missous, S Arscott, Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520 (IEMN), Centrale Lille-Institut supérieur de l'électronique et du numérique (ISEN)-Université de Valenciennes et du Hainaut-Cambrésis (UVHC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS)-Université Polytechnique Hauts-de-France (UPHF), Institute of Physics [Warsaw] (IFPAN), and Polish Academy of Sciences (PAN)

Subjects
Deep-level transient spectroscopy, Analytical chemistry, 02 engineering and technology, Electron, Activation energy, 01 natural sciences, Condensed Matter::Materials Science, [SPI]Engineering Sciences [physics], 0103 physical sciences, Materials Chemistry, Electrical and Electronic Engineering, Inorganic compound, ComputingMilieux_MISCELLANEOUS, 010302 applied physics, chemistry.chemical_classification, Chemistry, Photoconductivity, Doping, technology, industry, and agriculture, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, Condensed Matter Physics, Ray, Electronic, Optical and Magnetic Materials, Full width at half maximum, Atomic physics, 0210 nano-technology
Abstract

Capacitance-voltage (C-V) profiles have been measured for single delta -doped GaAs(Si) samples at various 2D sheet electron concentrations. The effect of temperature and incident light on the profiles has been monitored. In a heavily doped sample the authors have observed persistent photoconductivity, which they believe confirms the existence of the DX centre in delta -doped GaAs(Si). They have also noted a freeze-out of the equivalent 3D electron distribution with decreasing temperature, leading to an effective increase in the full width at half maximum (FWHM) of the C-V profile which can be attributed to electron trapping by DX centres. Using deep level transient spectroscopy they have observed a trap with activation energy approximately 350 meV in the heavily doped sample that exhibited persistent photoconductivity; this trap was not present in the lower doped delta -layers.

Published
1992

34. Thermal evolution of magnetic interactions in Ni nanowires embedded in polycarbonate membranes by ferromagnetic resonance

Author

A. Slawska-Waniewska, Ryszard Żuberek, H. Szymczak, J. Gieraltowski, J. Kazmierczak, A. Ghaddar, Frédéric Gloaguen, Pavlo Aleshkevych, Laboratoire de magnétisme de Bretagne (LMB), Université de Brest (UBO)-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Chimie, Electrochimie Moléculaires et Chimie Analytique (CEMCA), Institut Brestois Santé Agro Matière (IBSAM), Université de Brest (UBO)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institute of Physics [Warsaw] (IFPAN), and Polish Academy of Sciences (PAN)

Subjects
010302 applied physics, Materials science, Condensed matter physics, Nanowire, General Physics and Astronomy, 02 engineering and technology, Coercivity, Condensed Matter::Mesoscopic Systems and Quantum Hall Effect, 021001 nanoscience & nanotechnology, 01 natural sciences, Ferromagnetic resonance, Thermal expansion, Magnetization, Condensed Matter::Materials Science, Nuclear magnetic resonance, visual_art, 0103 physical sciences, visual_art.visual_art_medium, [CHIM]Chemical Sciences, Crystallite, Polycarbonate, 0210 nano-technology, Anisotropy
Abstract

International audience; Ni polycrystalline nanowires with diameters of 50, 80, and 100 nm were electrodeposited in cylindrical pores of track-etched polycarbonate membranes. Their magnetic properties were determined as a function of temperature using ferromagnetic resonance and magnetization measurements. At room temperature, the uniaxial anisotropy is equal to the shape anisotropy whereas an additional contribution is evidenced at low temperature. This additional contribution is attributed to magnetoelastic effects induced in the nanowires due to the different thermal expansion constants of Ni and polycarbonate. The analysis of magnetization processes in Ni nanowire arrays evidenced strong dipolar interactions inside the wires due to the domain structure. The coercive field of the nanowires was shown to be nearly a linear function of the temperature and could be accounted for temperature dependence of the uniaxial anisotropy.

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