| | | | | | | webmail : intra-extra| Accès VPN| Accès IST| Contact
11-07-2019
La métrologie (spectroscopie, mesures de temps ou de distances) ou encore la réalisation de réseaux optiques quantiques nécessitent des sources de photons uniques efficaces. Une équipe du SPEC à Saclay, en collaboration avec l'IQST d'Ulm en Allemagne, propose une voie originale pour obtenir une source de photons microondes uniques, simple, efficace et brillante.
11-03-2019
La métrologie (spectroscopie, mesures de temps ou de distances) ou encore la réalisation de réseaux optiques quantiques nécessitent des sources de photons uniques efficaces. Une équipe du SPEC à Saclay, en collaboration avec l'IQST d'Ulm en Allemagne, démontre expérimentalement une voie originale pour obtenir une source de photons microonde uniques, simple, efficace et brillante.
30-07-2018
Pure spin conductors could behave as nonlinear component in the high power regime, hereby opening up considerably the realm of functions realizable with magnetic materials. An additional feature is that these are continuously tunable by an external magnetic field.  
23-01-2018
La résonance magnétique a un impact important dans nos vies de tous les jours, de l’imagerie médicale au contrôle qualité dans la production de bière. Cette technique utilise de puissants aimants et des impulsions radio-fréquence ou micro-ondes pour révéler de faibles concentrations de molécules dans une substance.
23-11-2017
The Web site of the COSMICS project. The SPEC/GMT team of CEA coordinates the European H2020 FET-Open project "Cosmics" (Concepts and Tools in Molecular Spintronics) whose kick off meeting was held on November 27th and 28th, 2017. This project, stemming from a very selective call, focuses on the search for new hybrid devices, associating molecules and metallic magnetic electrodes, able to enrich the design of highly miniaturized electronic components.
23-01-2017
An international team published in Nature, the discovery and interpretation of a surprising form of biological collective motion:  They observed that millions of motile cells in dense bacterial suspensions can self-organize into highly robust collective oscillatory motion, while individuals move in an erratic manner.
01-06-2016
Les verres forment l’essentiel de nos matériaux du quotidien, et prennent une place croissante dans les technologies modernes (fibres optiques, etc…).
23-11-2011
K. Katsuyoshi, D. L'Hôte, S. Nakamae, M. Konczykowski, V. Mosser
Le théorème de fluctuation-dissipation, reliant l'intensité des fluctuations d'une observable à la réponse à une sollicitation, est un principe vérifié pour tous les systèmes à l'équilibre thermodynamique.
18-07-2011
( Version française) Stress corrosion - combined action of mechanical stress and corrosion by water from the surrounding atmosphere - is often the cause of crack propagation in glasses. A study by neutron reflectivity at the Laboratoire Léon Brillouin (IRAMIS / LLB) of samples of silica glass fractured under an atmosphere of heavy water (D2O) shows a high penetration of water into the glass.
19-04-2011
Measurement of the cardiac electrical activity allows following the heart dynamics. Usually measured with electrodes during an electrocardiogram (ECG), this activity can also be studied by monitoring the magnetic component, induced by the circulation of the heart electric currents. This is called "magnetocardiography (MCG).
16-09-2010
Eva Zakka-Bajjani, J. Dufouleur, N. Coulombel, P. Roche, D. C. Glattli, and F. Portier
( French version) Contact: Dr. Fabien PORTIER A conductor in equilibrium under a bias voltage shows current fluctuations proportional to its resistance and temperature. This type of noise is known as the Johnson-Nyquist noise, or equivalently, the thermal noise. In a quantum conductor, current fluctuations generate microwave photons which obey chaotic statistics (cf., blackbody radiation) if the conductor is at equilibrium.
14-04-2010
Benjamin Pigeau, Grégoire de Loubens, and Olivier Klein: Groupe Nanomagnétisme
In a vortex-state magnetic nanodisk, the static magnetization is curling in the plane, except in the disk center where it is pointing out-of-plane, either up (polarity p=+1) or down (p=-1). The lowest energy excitation mode of this ground state is the so-called gyrotropic mode [1], corresponding to a gyration of the vortex core around its equilibrium position at the center of the disk.
30-03-2010
( Version française) Researchers in the Instability and Turbulence Group of IRAMIS-SPEC have succeeded in experimentally characterizing the non linear mechanical response of an amorphous granular media across the jamming transition. They have demonstrated that global rigidity sets in via the critical growth of a correlation length.
16-03-2010
J. Scheibert, C. Guerra, F. Célarié, D. Dalmas and D. Bonamy
Depending on their fracture mode, materials are traditionally gathered into three distinct classes: (i) ductile materials that like metals deform plastically before their fracture (ii) quasi-brittle materials such as rock or concrete, where "non-visible" damage starts to accumulate through microcracking, up to coalescence that yields to catastrophic failure. (iii) brittle materials like oxide or polymer glasses... that deform elastically up to their fracture.
26-11-2009
H. Cao, A. Gukasov, I. Mirebeau, P. Bonville, C. Decorse, and G. Dhalenne
In geometrically frustrated magnetic compounds, the ground state is the result of a subtle equilibrium between different energy terms. Exotic short range magnetic orders, like spin ices or spin liquids, may be stabilised, in the absence of any chemical disorder. Presently, many  experimental  and theoretical works are devoted to their understanding. A crystal lattice where frustration plays an important role is the pyrochlore lattice.
17-11-2009
Making still smaller and less power consuming digital memories for mobile electronics? Scientists from CNRS and University Paris Sud XI (Laboratory of Solid State Physics, CNRS / Univ. Paris-Sud 11 and Institut Néel) and CEA-IRAMIS come to demonstrate the feasibility, thanks to a new class, said multiferroic, of materials combining unusual electrical and magnetic properties. This text is a translation of the joint press release from CEA-CNRS-Univ.
13-10-2009
Iouri Mukharsky, Andrei Penzev and Eric Varoquaux, Nanoeletronics group
If it truly does exist, a "supersolid" would represent a new state of matter that combines mechanical rigidity and superfluid properties. This would be a new phase of condensed matter, but whether such a state has indeed been discovered and how it can be reached is still far from clear. As reported in Physical Review B 80 (2009) 140504(R), researchers at SPEC have measured the low frequency elastic properties of solid helium-4 using ultra-sensitive acoustic techniques.
30-09-2009
F. Mallet, F. Ong, A. Palacios, F. Nguyen, P. Bertet, Denis Vion and D. Esteve
After the realization in 2002 of one of the first solid state quantum bits (qubits), scientists from the Quantronique IRAMIS-SPEC research group have performed a further step towards the realization of  an elementary quantum processor: the accurate and non destructive readout of such a qubit.
25-06-2009
Single molecule magnets grafted on carbon nanotubes : the first of its kind has been realized at the Molecular Chemistry and Materials Institute in Orsay (CNRS/University of Paris 11) in collaboration with the Institut Lavoisier de Versailles (CNRS/Université de Versailles Saint-Quentin), the Laboratoire de Chimie Physique (CNRS/Université Paris 11), the Molecular Electronics Laboratory (CEA-Saclay/SPEC) and the Néel Institut in Grenoble (CNRS/Université Joseph Fourier).
09-06-2009
( Version française) We thought we knew transistor physics fairly well and in particular the millions of MOSFETs (Metal Oxyde Semi-conducteur Field Effect Transistor) which can be found at the core of our computers. However, as early as 1994, a new generation of very high mobility MOSFETs lead to experiments where one could study the regime of extremely low density (Kravchenko et al 1994).
19-12-2008
H. le Sueur, P. Joyez, H. Pothier, C. Urbina, and D. Esteve
The Editors of the journal Physical Review Letters recently awarded the label "Editor's suggestion" to an article from the  Quantronics group of SPEC (Laboratory of Condensed Matter Physics) : "Phase Controlled Superconducting Proximity Effect Probed by Tunneling Spectroscopy, Phys. Rev. Lett. 100 (2008) 197002".
15-07-2008
D. Bonamy and L. Ponson (SPCSI), D. Santucci (Fysik Institutt Oslo)
Fracture is a phenomenon of everyday life: it is observable at all scales of condensed matter, from the atomic scale (in nanostructures) to the scale of our planet marked by fractures in the continental plates. But, can we find a unifying model to describe the phenomenon? The dynamics of fracture is complex.
16-04-2008
Delphine Lebeugle, Dorothée Colson, Anne Forget, Michel Viret (IRAMIS/SPEC CEA-Saclay) Arsen Goukassov, Alexandre Bataille (IRAMIS/LLB CEA-Saclay) Magnetic materials are heavily used in the dynamic storage of information (hard disk drive, head for reading). For these applications, they are most often designed in the form of thin films. This was achieved after the birth of the spin electronics or "spintronics" and the discovery of the giant magnetoresistance.
25-09-2007
Le mélange des fluides très visqueux intervient dans de nombreux procédés industriels, mais est également présent dans la vie courante. Pour mélanger une pâte à gâteau, par exemple, un enfant va intuitivement remuer les ingrédients avec une cuillère.
27-06-2007
Researchers at the Institute of Electronics, Microelectronics and Nanotechnologie (IEMN / CNRS – Universités Lille 1 and Valenciennes, Institut supérieur de l’électronique et du numérique-ISEN) and  the Solid-state Physics Division at the French Atomic Energy Agency (CEA), have succeeded in making transistors from carbon nanotubes on a silicon substrate.
08-06-2007
Nuclear magnetic resonance (NMR) is an indispensable technique for studying matter. It can be applied to medical imaging (MRI) to obtain 2D and 3D images of the human body. While it opens the door to a wealth of physicochemical information by harnessing the fundamental properties of matter, NMR remains a technique with poor sensitivity, making it very difficult to use on small quantities of solid or heterogeneous material.
28-03-2007
M.-A. Dubois1, L. H. Emmons2, L. Cournac3, P. Chatelet4, N. C. A. Pitman5, V. Vilca5, & L.-F. del Aguila6
1CEA Saclay, DSM/DRECAM/Service de Physique de l ’Etat Condensé, L ’Orme des Merisiers, 91191 Gif sur Yvette, France 2Department of Zoology NHB 390 MRC 108, Smithsonian Institution, P.O.
07-02-2007
M. Roger1, D.J.P Morris2, D.A. Tennant3,4, M.J. Gutmann5, J.P. Goff2, J.-U. Hoffmann3, R. Feyerherm3, E. Dudzik3, D. Prabhakaran6, A.T. Boothroyd6, N. Shannon7, B. Lake3,4 & P.P. Deen8. 1Service de Physique de l’Etat Condensé (CNRS/MIPPU/URA 2464), DSM/DRECAM/SPEC, CEA Saclay, P.C. 135, F-91191 Gif sur Yvette, France. 2Dept. of Physics, University of Liverpool, Oliver Lodge Laboratory, Liverpool L69 7ZE, UK.
27-01-2007
A. Chiffaudel, F. Daviaud, B. Dubrulle, C. Gasquet, R. Monchaux, V. Padilla, avec la participation de L. Marié et F. Ravelet, DSM/DRECAM/SPEC
Collaboration VKS : CEA – ENS Lyon – ENS Paris -
Many research teams aim at understanding of the origin and behavior of the magnetic field of planets and stars. The VKS1 collaboration (gathering researchers at CEA, CNRS, Ecoles normales supérieures in Lyon and Paris) has succeeded in generating a magnetic field from a highly turbulent liquid sodium flow in a laboratory experiment.
07-08-2006
J. Gabelli1, G. Fève1, J.-M. Berroir1, B. Plaçais1, A. Cavanna2, B. Etienne2, Y. Jin2, D. C. Glattli1,3
A mixed team from ENS / CNRS / CEA-Saclay (SPEC) of the Pierre Aigrain Laboratory has for the first time highlighted the remarkable behavior of an electronic circuit when its miniaturization is extreme. These results are published in the journal Science. Researchers have shown that the basic laws of electricity, established since 1845, can no longer describe the properties of an electronic circuit when its dimensions reach the nanometer scale.

 

Retour en haut