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

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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).

 

Seminar : Atomic Resolution Transmission Electron Microscopy experiments on single radiation-sensitive nanoparticles

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Elvio Carlino, Head of TEM laboratory, a part of the Centre for Electron Microscopy (CEM) of IOM-CNR

Elvio Carlino
Italian National Research Council  Trieste/Lecce, Italy

Novembrer 16 th 2017 -11 h – LCI Salle du Conseil

Abstract :

Transmission Electron Microscopy (TEM) is widely used to study the properties of the matter at the highest spatial resolution. There is a wide literature that reports on the study of single nanoparticles of inorganic material showing how fundamental subtle physical effects can be understood by TEM experiments. High Resolution TEM (HRTEM) enables to directly access the structural properties of individual particles correlating the structure, the crystal perfection, or the presence of defects, to the their behavior enabling the development of new powerful materials for a huge variety of applications. The study of single particles enables to distinguish in a batch of nanoparticles the differences between them and the relevant influence on macroscopic behavior of the material. In the case of radiation sensitive material, like biologic material or nano-crystalline salt drugs, standard HRTEM approaches on single particles could fail due to the damage induced by the high-energy electrons on the specimen. Here will be shown how HRTEM imaging on pristine radiation sensitive single nano clusters can indeed be obtained, enabling to directly image the crystalline properties of soft matter and biologic nanoparticles that was believed not possible to study by atomic resolution TEM.

Journées du CLub EEA : Véhicule autonome et transport intelligent

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Les journées de la section électronique du club EEA se dérouleront à l’Université de Valenciennes et du Hainaut Cambrésis les 9 et 10 novembre 2017.

2017/2018 étant placée sous le signe de l’année du Canada à l’UVHC, l’IEMN-DOAE organise, en partenariat avec le LAMIH, les prochaines journées du club EEA sur le thème « Véhicule autonome – Transport intelligent. »

 

2 dates à retenir pour venir à l’université de valenciennes participer ou présenter vos travaux sur l’une des thématiques suivantes :

  • Capteurs, microsystèmes et mécatronique
  • Système embarqué
  • Véhicule autonome
  • Communication inter-véhicules
  • perception de l’environnement/localisation

Des conférences invitées, viendront en introduction de ces thématiques.

4 personnalités invitées ont d’ores et déjà confirmé leur présence :

  • Eric Ollinger : Adjoint à la Sous-direction de la gestion du réseau routier non concédé et du trafic Ministère de l’écologie, du développement durable et de l’énergie Direction générale des infrastructures, des transports et de la mer (DGITM) Direction des infrastructures de transport
  • Didier Nicholson : Research Project Director à VITEC, Vidéo Innovations pour la session « Perception de l’environnement/localisation »
  • Helmut Seidel : professeur à Sarrebruck dans le domaine des microsystèmes, application à l’automobile, pour la session « Capteurs, microsystèmes et mécatronique »
  • Soumaya Cherkaoui : professeure au Département de Génie Électrique et de Génie Informatique, Directrice Interlab, Université de Sherbrooke pour la session « Véhicule autonome »

Dates importantes

Inscriptions

  • Doctorants :90€
  • non-doctorants :120€

Date limite d’inscription et soumission des résumés (1 page A4) : 23 octobre 2017

Appel à participation

 

Seminar : Inside Nature Materials

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Maria Maragkou,

Dr. Maria Maragkou,
Senior Editor at Nature Materials.

7 November 2017 at 14h00
Amphitheater – IEMN-LCI

ABSTRACT: 
Since its launch in 2002, Nature Materials remains a leading journal in the field of materials science across many disciplines, aiming at publishing cutting edge science for the relevant scientific communities as well as disseminating exciting results among the wider readership of materials scientists. This talk will describe how these principles shape the editorial process in Nature Materials and other journals within the Nature family, amidst a rapidly changing scientific publishing landscape, underlining the key points from submission of original research papers to publication.

About Maria Maragkou:

Maria joined Nature Materials in January 2015, after briefly working in Nature Photonics. She has a first degree in electrical and computer engineering from the University of Patras, Greece, and a PhD in physics from the University of Southampton, UK on the topic of light-matter interactions in semiconductor microcavities. She then worked as a postdoctoral researcher at the Universidad Autónoma de Madrid, Spain and at the École Normale Superiéure in Paris, studying quantum optics with epitaxial quantum dots.

 

Seminar: Embedded many-body perturbation theory for organic electronics

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Jing Li

Jing Li
Institut Néel, CNRS and Grenoble Alpes University
Equipe : Théorie de la matière condensée
Tuesday, October 24th 11.30 am/ Salle du conseil LCI

Abstract :
The description of the electronic and optical properties of complex supramolecular systems such as
those of interest in organic electronics represents a severe challenge for first principles techniques,
owing to the large molecular dimensions and to the ubiquitous presence of disorder. We will report
on our original hybrid QM/MM scheme merging many-body perturbation theory (GW formalism
and Bethe-Salpeter equation) with accurate classical polarizable models of atomistic resolution. Our
results for bulk pentacene prove that the gap is insensitive to the partitioning of molecules in QM
and MM subsystems, as a result of the mutual compensation of quantum and classical
polarizabilities, clarifying the relation between polarization energy and charge delocalization. Our
embedded GW calculations, are capable to accurately describe ionization energies and electron
affinities at crystal surfaces of penatcene and perfluoropentacene from first principles.

The electronic and optical properties of the paradigmatic F4TCNQ-doped pentacene in the lowdoping
limit are investigated by a combination of state-of-the-art GW and Berthe-Salpeter manybody
ab initio methods accounting for environmental screening effects, and a carefully
parametrized model Hamiltonian. We demonstrate that while the acceptor level lies very deep in the
gap, the inclusion of electron-hole interactions strongly stabilizes dopant-semiconductor charge
transfer states and, together with spin statistics and structural relaxation effects, rationalize the
possibility for room-temperature dopant ionization. Our findings reconcile available experimental
data, shedding light on the partial vs. full charge transfer scenario discussed in the literature, and
question the relevance of the standard classification in shallow or deep impurity levels prevailing
for inorganic semiconductors.

References :
J. Li, G. D’Avino, I. Duchemin, D. Beljonne, X. Blase, J. Phys. Chem. Lett. 7, 2814 (2016)
J. Li, G. D’Avino, A. Pershin, D. Jacquemin , I. Duchemin, D. Beljonne, X. Blase, Phys. Rev.
Materials, 1, 025602 (2017)

Une journée autour de l’électronique imprimée

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En partenariat avec l’association AFELIM, CAPTRONIC et l’IEMN vous proposent une journée autour de l’électronique imprimée au sein de l’IEMN afin de découvrir le développement de la filière et des multiples applications.

Objectif :  Faire un tour d’horizon des différents maillons de la chaîne : innovations, formulations, impressions, afin d’identifier les applications possibles.

PROGRAMME

  • 10H00 Accueil des participants
  • 10h30 Introduction
    Présentation de CAPTRONIC, Edmond PATERNOGA
  • 10H50 Présentation AFELIM, association française de l’électronique imprimée
    Anne-Lise MARECHAL, AFELIM
  • 11H00 Encres argent et autres matériaux pour circuits
    Henri HAPPY, IEMN
  • 11H30 Capteurs sur substrats souples
    Christophe MATHIEU, LINXENS
  • 12H00 L’impression « électronisée »
    Laurent LENGLET, CENTRE TECHNIQUE DU PAPIER
  • 12H30 Buffet
  • 14H00 Encres et colles pour l’électronique imprimée
    Alexandre LONG, PROTAVIC INTERNATIONAL
  • 14H30 Application : Dalles tactiles
    Laurent SCHNEIDER, KERDAINO
  • 15H00 Le papier devient intelligent
    Victor MADELAINE, ARJOWIGGINS CREATIVE PAPERS
  • 15H30 Présentation de la plateforme technologique LEAF
    Emmanuel DUBOIS, IEMN
    Conclusions : Opportunités et Besoins potentiels, Questions/Réponses
  • 16H00 Visite de la plateforme LEAF

INFORMATIONS PRATIQUES

Date et lieu : Jeudi 19 octobre 2017 de 10h00 à 16h00
Institut d’Electronique, de Microélectronique et de Nanotechnologie
Avenue Poincaré – CS 60069 – 59652 VILLENEUVE D’ASCQ CEDEX

Prix  : Gratuit, les frais de cette journée sont pris en charge par Cap’tronic

Contact  : Edmond PATERNOGA – paternoga@captronic.fr

Seminar: Scalable High-Throughput mm-Wave “Wireless Fiber” Systems

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Amin Arbabian
Assistant Professor, Department of Electrical Engineering
Stanford University
Wednesday, October 18th 11am / IEMN Amphitheater

Abstract:
Commercial mm-wave systems are addressing a variety of applications in communication and radar. However, scaling of these systems to larger throughputs and spatial coverage is limited by hardware constraints. This work explores challenges in the silicon integration of scalable high-throughput “Wireless Fiber’’ links that use the spatial and spectral degrees of freedom by exploiting multiplexing in LoS MIMO environments and at extremely high bandwidths. We examine tradeoffs in the partitioning of functionality between the transmitter and receiver as well as the analog and digital domains and investigate a new scalable analog processing architecture for the receiver network. The design of a 4×4 160 Gbps system will be discussed. In addition to this system, we will also present an energy-efficient 130GHz 12.5Gbps OOK system operating with 1.55pJ/bit/m at >5m range. Mm-wave plastic dielectric waveguides for high-speed links and signal distribution in mm-wave systems will also be discussed.

Short Bio:
Amin Arbabian received his Ph.D. degree in EECS from UC Berkeley in 2011 and in 2012 joined Stanford University, as an Assistant Professor of Electrical Engineering. His research interests are in mm-wave and high-frequency circuits and systems, imaging technologies, and ultra-low power sensors and implantable devices. Prof. Arbabian currently serves on the steering committee of RFIC, the technical program committees of RFIC and ESSCIRC, and as associate editor of the IEEE Solid-State Circuits Letters (SSC-L) and the IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology (J-ERM). He is the recipient or co-recipient of the 2016 Stanford University Tau Beta Pi Award for Excellence in Undergraduate Teaching, 2015 NSF CAREER award, 2014 DARPA Young Faculty Award (YFA) including the Director’s Fellowship in 2016, 2013 Hellman faculty scholarship, and best paper awards from several conferences including ISSCC (2010), VLSI Circuits (2014), RFIC symposium (2nd place, 2008 and 2011), ICUWB (2013), PIERS (2015), and the MTT-S BioWireless symposium (2016).

Seminar: Silicon Integrated Systems for Healthcare

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Amin Arbabian
Assistant Professor, Department of Electrical Engineering
Stanford University
Wednesday, October 18th 5.30 pm / Amphi Jean Noël Decarpigny, ISEN Lille

Abstract:
Advances in healthcare technologies have mainly focused on therapeutics, interventional procedures, and “late-stage” diagnostics. These steps have undergone significant improvements, leading to higher survival rates and enhancements in quality of life. Nevertheless, current trends are unsustainable due to the inadequate outcomes on specific critical diseases and skyrocketing national healthcare costs. An important example is cancer, where mortality rates have not seen major improvements, even with the tremendous technological advances in diagnostic imaging tools over the last four decades.

In this talk I will outline our efforts in better marrying technology and healthcare with new systems that 1) enable continuous “Nyquist” imaging and screening to enable preventive/predictive care, and 2) introduce smart implants for precision monitoring and closed-loop therapies. Preventive screening through continuous monitoring has the potential to fundamentally revamp our understanding of disease as well as targeted therapy. Today, the human body is monitored infrequently, perhaps on an annual basis and with a low “resolution”. This is in contrast with advanced electronic systems (many of which our community designs and ships), which are frequently monitored and calibrated. I will summarize a few example projects that aim to address these issues, including portable, semiconductor-based, “Tricorder” imaging systems, ultrasound-powered implantable devices that can measure, detect, and act upon local physiological changes through closed-loop neuromodulation or “electroceuticals”, and finally our new investigation of a noninvasive methods of neuromodulation based on ultrasonic excitation.

Short Bio:
Amin Arbabian received his Ph.D. degree in EECS from UC Berkeley in 2011 and in 2012 joined Stanford University, as an Assistant Professor of Electrical Engineering. His research interests are in mm-wave and high-frequency circuits and systems, imaging technologies, and ultra-low power sensors and implantable devices. Prof. Arbabian currently serves on the steering committee of RFIC, the technical program committees of RFIC and ESSCIRC, and as associate editor of the IEEE Solid-State Circuits Letters (SSC-L) and the IEEE Journal of Electromagnetics, RF and Microwaves in Medicine and Biology (J-ERM). He is the recipient or co-recipient of the 2016 Stanford University Tau Beta Pi Award for Excellence in Undergraduate Teaching, 2015 NSF CAREER award, 2014 DARPA Young Faculty Award (YFA) including the Director’s Fellowship in 2016, 2013 Hellman faculty scholarship, and best paper awards from several conferences including ISSCC (2010), VLSI Circuits (2014), RFIC symposium (2nd place, 2008 and 2011), ICUWB (2013), PIERS (2015), and the MTT-S BioWireless symposium (2016).

Séminaire « ExCELSiOR » : Synthesis and Characterization of Perovskite Films

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Jaume Llacer Martinez (doctorant dans le groupe NAM6)

Salle du conseil, Vendredi 6 octobre 2017, 11h00.

J. L. Martinez

Jaume Llacer Martinez débute une thèse en cotutelle avec l’université de Mons sur l’élaboration et caractérisation par microscopie AFM et SMM de matériaux pour le photovoltaïque. Il a effectué un master « matériaux et nanosciences » à l’université de Strasbourg et l’école européenne de chimie, polymères et matériaux.

Il nous présente les principaux résultats obtenus lors de son stage à l’IMEC (Leuven) sur le développement des LED à base de pérovskites.

 

Contact :
didier.theron@iemn.univ-lille1.fr