Séminaire : Molecular spin coupling at the tip of a STM

Par Laurent Limot
chercheur CNRS à l’IPCMS à Strasbourg
Contact : limot@ipcms.unistra.fr

Mercredi 16 avril 2018 à 10h30
IEMN Salle du conseil – Villeneuve d’Ascq

 

Abstract :

Recent advances in addressing and controlling the spin states of a surface-supported object (atom or molecule) have further accredited the prospect of quantum computing and of an ultimate data-storage capacity [1]. Information encoding requires that the object must possess stable magnetic states, in particular magnetic anisotropy to yield distinct spin-dependent states in the absence of a magnetic field together with long magnetic relaxation times. Scanning probe techniques have shown that inelastic electron tunneling spectroscopy (IETS) within the junction of a scanning tunneling microscope (STM) is a good starting point to study the stability of these spin states [2]. STM-IETS allows for an all-electrical characterization of these states by promoting and detecting spin-flip excitations within the object of interest. As spin excitations need however to be preserved from scattering events with itinerant electrons, single objects are usually placed on non-metallic surfaces such as thin-insulating layers or superconductors. In this sense, new approaches to improve the detection of spin-flip excitations are desirable. With this purpose we present here a novel strategy based on the molecular functionalization of a STM tip. We study the surface magnetism of a simple doubledecker molecule, nickelocene [Ni(C5H5)2], which is adsorbed directly on a copper surface. By means of X-ray magnetic circular dichroism and density functional theory calculations, we show that nickelocene on the surface is magnetic (Spin = 1) and possesses a uniaxial magnetic anisotropy, while IETS reveals an exceptionally efficient spin-flip excitation occurring in the molecule [3]. Interestingly, nickelocene preserves its magnetic moment and magnetic anisotropy not only on the surface, but also in different metallic environments. Taking advantage of this robustness, we are able to functionalize the STM tip with a nickelocene [3,4], which can then be employed as a portable source of inelastic excitations. As we will show during the talk, IETS can then be used to probe the interaction between a surface-supported object and the nickelocene tip, including a magnetic interaction.

M. Ormaza1, P. Abufager2, B. Verlhac1, N. Bachellier1, M.-L. Bocquet3, N. Lorente4, and Laurent Limot1,*
1Université de Strasbourg, CNRS, IPCMS, UMR 7504, F-67000 Strasbourg, France
2Instituto de Física de Rosario, CONICET, Universidad Nacional de Rosario, Argentina
3Ecole Normale Supérieure, UPMC Univ. Paris 06, CNRS, 75005 Paris, France
4CFM/MPC and DIPC, 20018 Donostia-San Sebastián, Spain

References
[1] F.D. Natterer et al., Nature 543, 226 (2017); T. Choi et al., Nat. Nanotech. 6 (2017)
[2] A.J. Heinrich, J.A. Gupta, C.P. Lutz, and D.M. Eigler, Science 306, 466 (2004)
[3] M. Ormaza et al., Nano Lett. 17, 1877 (2017)
[4] M. Ormaza et al., Nat. Commun. 8, 1974 (2017)

 

 

date_04-05

Conference : Prototype of Terahertz Communications at 300 GHz: Devices, Packages

HO-JIN-SONG_Pohang_University_of_Science_and_Technology-POSTECH

Dr. HO-JIN SONG, Pohang University of Science and Technology (POSTECH)

Tuesday 5 April at 10h30

Conférence 10:30
Anfiteather – IEMN-LCI Institut d’Electronique, de Microélectronique et de Nanotechnologie U.M.R C.N.R.S 8520 – Laboratoire Central – Cité Scientifique – Avenue Poincaré – CS 60069 – 59652 VILLENEUVE D’ASCQ CEDEX

Intervenants

Pohang-University-of-Science-and-Technology_logo

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Séminaire : A propos de la dynamique non régulière

Par Alain Léger
Directeur de Recherche au CNRS
Contact : leger@lma.cnrs-mrs.fr

Mercredi 28 mars 2018 à 14h00
IEMN Ampli LCI – Villeneuve d’Ascq

Abstract :

Cet exposé va présenter quelques aspects, d’abord introductifs, puis plus récents de la mécanique non régulière. Nombre de situations, conditions au bord ou lois de comportement, fournissent des exemples de non régularité en mécanique. On se concentrera principalement sur le cas du contact et du frottement mais plusieurs aspects fondamentaux seraient identiques dans les cas de la plasticité, de l’endommagement, etc… Dans tous les cas l’introduction de conditions non régulières en mécanique des milieux continus conduit à des problèmes mathématiques ouverts et difficiles. On essaiera pour cela de préciser minutieusement l’état des lieux, en forme de liste des problèmes résolus ou ouverts, afin que soient clarifiées les situations où il est légitime ou non d’utiliser des résultats dans différents domaines de la physique, et l’on observera que ce sont alors des modèles simples qui, pour autant qu’ils soient bien choisis, apportent des informations qualitatives là où des modèles plus proches de la physique seraient inaccessibles.

On rappellera que la non régularité supprime la possibilité de se référer au cadre classique de la théorie des équations différentielles ou aux dérivées partielles. Après quelques résultats, énoncés dans le cas d’un système mécanique très simple mais généralisables à tous les problèmes discrets, une partie importante de l’exposé sera consacrée à l’étude de la réponse à une sollicitation périodique comme cela est classique dans l’étude qualitative des systèmes dynamiques.

Dans un premier temps le système mécanique sera linéaire, ce qui en rendra les résultats utilisables qualitativement dans nombre de domaines de physique, d’acoustique ou de vibrations. Une attention particulière sera portée à la transition entre des zones de comportements différents, et l’on notera qu’aucune transition au chaos n’est observée lorsque la seule non linéarité est due au contact et au frottement. Dans un deuxième temps on ajoutera une non linéarité régulière de type grandes déformations. On verra alors que la réponse peut comprendre des zones de comportement non périodique, ce qui amènera, en conclusion, à interroger le couplage entre différents types de non linéarités.

 

H.D.R. Contributions à la compréhension du canal de propagation sans-fil MIMO : modèles, applications et perspectives – GAILLOT, DAVY

HABILITATION A DIRIGER DES RECHERCHES – UNIVERSITE DE LILLE

DAVY GAILLOT
27 mars à 10h30
Amphithéâtre 1A12 – IUT-A

 

Ecole doctorale : Sciences Pour l’Ingénieur (SPI)
Laboratoire/Etablissement : IEMN-IRCICA, Université de Lille – FST
Discipline : SCIENCES PHYSIQUES

LES MEMBRES DU JURY :

Garant de l’habilitation :

  • MME. LIENARD Martine, Professeure de l’Université de Lille – FST

Rapporteurs :

  • M. BENLARBI-DELAI Aziz, Professeur de Sorbonne Université
  • M. EL ZEIN Ghaïs, Professeur de l’INSA Rennes
  • M. VAUZELLE Rodolphe, Professeur de l’Université de Poitiers

Examinateurs :

  • M. CLAVIER Laurent, Professeur de l’Institut Mines TELECOM Lille-Douai
  • M. OESTGES Claude, Professeur de l’Université Catholique de Louvain, Belgique
  • SOUTENANCE : Mardi 27 Mars 2018 à 10h30, IUT-A Amphi 1A12

HDR_2018_Davy Gaillot

Les Mardis de l’Innovation : L’enjeu global du stockage de l’énergie pour l’avenir de l’internet des objets, des énergies alternatives et de la mobilité

Mardi 20 mars 2018

Accueil 18:00 – Conférence 18:30 – 20:30
CNRS, 3 rue Michel-Ange, 75016 Paris

Les technologies de stockage de l’énergie sont au cœur d’un enjeu mondial considérable. L’avenir de beaucoup d’innovations est lié à d’importants progrès dans les capacités de stockage compact et de recharges rapide des batteries (l’automobile et toutes les autres formes de mobilité, jusqu’au smartphone notamment). Les grandes énergies alternatives (éolien et solaire), n’étant pas continue, leur efficacité dans les réseaux futurs est également liée à l’amélioration du stockage de l’électricité. Quant au monde gigantesque des objets connectés qui se prépare, il est très consommateur de batteries miniaturisées à très longue durée de vie sans rechargement. Si aujourd’hui le lithium est le matériau phare, avec de multiples combinaisons, d’autres matériaux et des technologies alternatives comme la pile à combustible progressent rapidement. Voyage au cœur d’une compétition mondiale allant de la recherche avancée sur l’efficacité des batteries et leur recyclage à l’accès aux matériaux et débouchant sur une bataille industrielle mondiale dominée aujourd’hui par l’Asie.

Intervenants

  • François BARSACQ, PDG, EasyLi, concepteur et fabricant de solutions de stockage d’énergie
  • Patrice SIMON, Réseau sur le Stockage Electrochimique de l’Energie, RS2E
  • Christophe LETHIEN, Institut d’électronique, de microélectronique et de nanotechnologie , IEMN, Université de Lille, CNRS
  • Nicolas LECLERE, Responsable Pôle Innovation Motorisations Electrifiées, Groupe PSA

Séminaire : « Quantitative Scanning Probe Microscopy Techniques for Heat Transfer Management in nanomaterials and nanodevices »

mardi 20 mars à 17h45 – ISEN Lille

Séverine Gomès
CNRS researcher, Micro and Nanoscale Heat Transfer group at the Centre for Energy and Thermal Sciences, Lyon University

Abstract: The control of heat flow is central to all technologies. According to the first law of thermodynamics, heat is the universal consequence of physical activity. At the same time modern material science and technology is increasingly devoted to the control of matter on the nanoscale and miniaturization of device elements well below 100 nm. By nano-structuring materials their physical properties may be engineered to achieve optimal performance. Examples include materials used in renewable energy generation (thermoelectric, photovoltaics) and structural composites. Thermal control is the dominant problem in many of these fields. For example, the continuous linear scaling of clock frequency in silicon device technology has been suspended for the last ten years as a direct consequence of the decreasing element size and increasing power density in VLSI systems. This is the first aspect of Moore’s law to fail and it has failed directly because of thermal management problems at the nanoscale.

The flow of heat at the nanoscale is completely different from that experienced in macroscopic systems. The dominant phonon wavelengths at room temperature are of order a nanometer with ballistic mean-free path extending from tens of nanometers (in copper) to hundreds of nanometers in Si. Accordingly, at the nanoscale heat flow in solids ceases to be entirely diffusive and may, indeed, be quantized. Convection is suppressed. Radiative transport, where significant, takes place in the near field, since the wavelength of thermal photons is approximately 10 µm at room temperature. Accordingly, the normal methods of modelling and design used for macroscopic thermal work are completely inappropriate.

Effective tools for thermal measurement at the nanoscale are limited. The highest spatial resolution systems which are used for quantitative thermal measurement are based on optical effects, such as IR thermal emission, Raman spectroscopy or photo-reflectance. The spatial resolution of all of these methods is limited to 500 nm or greater. The key technique for thermal measurement at the nanoscale is Scanning Thermal Microscopy (SThM), but this remains highly non-quantitative in normal use. The need is for a complete thermal measurement and modelling technology for use at the nanoscale.

In this talk I will outline our efforts in better understanding the heat transfer and measuring thermal properties at the micro and nanoscales. I will give my feedback after four years as scientific coordinator of a European large scale- NMP Project QUANTIHEAT that was centered around the SThM technique to solve the problem of thermal metrology at the nano-scale and delivering validated standards, methods and modelling tools for nano-thermal design and measurement and gathered 21 strategic partners in Europe.

Short bio:
Dr Séverine Gomès received her European PhD in Physics at the University of Reims, France in 1999.
She is a permanent CNRS researcher, head of the Micro and Nanoscale Heat Transfer group at the Centre for Energy and Thermal Sciences (CETHIL), a common center of the National Institute of Applied Sciences in Lyon, CNRS and the University Claude-Bernard of Lyon.
She was recruited in 2001 by CNRS in the area of Scanning Thermal Microscopy (SThM), a scanning probe microscopy method with which she worked during her PhD in collaboration with the the group of Hubert Pollock and Azzedine Hammiche at Lancaster University (ULANC, UK). She was awarded the CNRS Bronze Medal in 2005 for her pioneering works on SThM.
Her main research interests deal with the development and the application of SThM and electrical methods with the goals of studying heat generation and transport at micro and nanoscales and measuring thermal properties of nanostructured materials and local temperature. During 8 years (2007-2014) she was co-responsible along with Prof. O. Kolosov (ULANC), for the ‘Local Probes’ group in the ‘Advanced Metrology’ axis of the CNRS-sponsored European Research Network: ‘Thermal NanoSciences and NanoEngineering’. From dec. 2013 to nov. 2017, she was the scientific coordinator of the European large scale- NMP Project QUANTIHEAT.

Contact :
Séverine Gomes – CETHIL UMR 5008
Mail : Severine.gomes@insa-lyon.fr
Phone : 04 72 43 64 28

Séminaire CINTRA – THALES

A l’IEMN , en salle du conseil le Jeudi 8 Mars 2017 à partir de 9h15
 
UMI 3288 CINTRA, CNRS – NTU Singapore – Thales : Research activities and recent achievements
 
P. Coquet, Univ. of Lille – Director of CINTRA, B.K. Tay, NTU Singapore – Deputy Director, Q. Dinh, Thales Singapore – Deputy Director, D. Birowosuto.
Abstract:
CINTRA UMI 3288 is a joint laboratory between CNRS, Nanyang Technological University and Thales Group. It is located in Singapore and is developing research activities on Nano-electronics and Nano-photonics technologies. http://cintra.ntu.edu.sg/Pages/default.aspx
IEMN is one of the historical partners of CINTRA and there are several on-going projects between IEMN and CINTRA. The objective of the presentation will be to give an overview of the recent activities developed in CINTRA with the perspective of initiating new joint projects.

The 3 research thrusts of CINTRA will be detailed.
  • Carbon based Materials and Devices: Carbon nanotubes, graphene, BN, foam like materials, with applications in RF, 3D integration, thermal management, energy storage 
  • New Nano-materials and Structures: 2D TMD, nanowires, defect induce emitters, with applications in nano light sources, quantum sensing, gas sensing, radiation detection, energy harvesting
  • Nano-photonics Technologies: nanostructured optical fibers, III-V 

http://cintra.ntu.edu.sg/Pages/default.aspx

http://www.ntu.edu.sg/AboutNTU/CorporateInfo/Pages/Intro.aspx

Séminaire MNMB : Yannick Rondelez, ESPCI

Yannick Rondelez
chercheur CNRS au laboratoire Gulliver à l’Ecole Supérieure de Physique et de Chimie Insdustrielle de la ville de Paris

mercredi 7 février 2018
à 14h00, IEMN, Amphi. LCI
.

Abstract:

Genetic polymers (DNA, RNA and analogues) and molecular programming techniques open unprecedented opportunities for the creation of molecular-scale information systems. For example, reaction networks with arbitrary topologies, build form synthetic DNA oligonucleotides can display rich non-linear behaviour. We can therefore reproduce in test tubes the fundamental dynamical systems underlying cell-scale computation, like oscillators, bistable switches, etc. In addition, molecular circuits open the route to a number of technological applications. Artificial molecular circuits can be combined with high throughput microfluidics techniques to implement highly parallel signal processing tasks in moleculo. I will discuss in particular a stochastic molecular optimisation technique addressing the challenge of protein design, as well as diagnostic applications.

Biographie:

Yannick Rondelez est actuellement chercheur au CNRS au laboratoire Gulliver (UMR 7083), à l’ESPCI. Après une formation académique en Physico Chimie à l’Ecole Normale supérieure de Cachan, il fait une thèse sur les modèles synthétiques de métallo-enzymes avant de partir au Japon pour un post-doc centré sur la biophysique (étude des protéines-moteurs). De retour en France, il travaille dans le consulting (créativité et heuristique) avant d’être embauché au CNRS, d’abord au Japon (LIMMS). En 2016, il déménage son groupe à l’ESPCI et développe un projet de recherche sur l’information au niveau moléculaire et la manière dont on peut rationnellement assembler des composants chimiques simples pour obtenir des systèmes dynamiques complexes.

Contact :
Yannick Dusch, Dr.
Maître de Conférences / Associate Professor
Tél. 03 20 19 18 16

GDRe Thermal Nanosciences and Nanoengineering Workshop

This second workshop of the Thermal Nanosciences and Nanoengineering GDRe will take place on the 23-24 November 2017 in Lille and is intended to map the today’s activities in the field of small scale heat transfer.

link: http://microelecsi.iemn.univ-lille1.fr/gdrelille/

Evelyne Lampin & Jean-François Robillard, IEMN local organizers


Deadlines

Abstract submission before October 27rd, 2017.

Online registration before November 6th, 2017.


Le GdRe Thermal NanoSciences and NanoEngineering est un groupement de recherche européen qui a débuté en Janvier 2015 et qui s’achèvera en Décembre 2019.

Coordonnateur : Sebastian Volz, EM2C, UPR CNRS 288, INSIS

Séminaire autour de la manipulation de spin dans les nanostructures de semiconducteurs

Physics of electron g-factors in semiconductor nanostructures

Athmane Tadjine (doctorant dans le groupe physique)
Salle du conseil, mardi 16 novembre 2017, 14h00.

Normalized density of g0−gz on each atom of a spherical nanocrystal of CdSe (diameter = 9 nm) for a magnetic field along z. The density is shown in the xOy (a) and xOz (b) planes passing through the center of the sphere. These data can be seen as the intensity of the local orbital component μl(r) of the magnetic moment (red arrow) induced by the circulating current [depicted by the circular arrow in (a)] generated by the spin-orbit coupling. The atoms are represented by black dots. (c) and (d) are same as (a) and (b), respectively, but calculated using the analytic envelope wave function

The manipulation of the electron spin in semiconductor nanostructures requires the knowledge of the electron g-factor. In this work, we revisit the physics of the electron g-factor in nanostructures of various shape, size, dimensionality (0D-3D) and composition. Our investigation is based on a combination of atomistic and analytical calculations.

We show that, for a given compound, the electron g-factors follow a universal law that just depends on the energy gap, in particular along rotational symmetry axes. We demonstrate that the orbital magnetic moment density strongly depends on the shape of the nanostructure but the total (integrated) magnetic moment is independent of the shape and therefore of the electron envelope wavefunction. The physical origin of this non-trivial behavior is explained.
We deduce that the bulk component of the g-factor is isotropic and that g-factor anisotropies entirely come from surface effects.

Athmane Tadjine (1), Yann-Michel Niquet (2), and Christophe Delerue (1)

1 Univ. Lille, CNRS, Centrale Lille, ISEN, Univ. Valenciennes, UMR 8520-IEMN,F-59000 Lille, nFrance
2 Université Grenoble Alpes, INAC-MEM, L Sim, Grenoble, France and CEA, INAC-MEM, L Sim, 38000 Grenoble, France

Reference: A. Tadjine, Y.-M. Niquet, and C. Delerue, Phys. Rev. B 95, 235437 (2017).