 | 17th ETSF Workshop on Electronic Excitations: Advanced Greens function methods
M. Gruning et al.
Date: October 2, 2012 to October 5, 2012
Location: Coimbra (Portugal)
Since its first edition in 1995, the ETSF (former Nanoquanta) workshop has pioneered a new vision of theoretical electronic structure, through the appellation theoretical spectroscopy. The success of this framework, uniting several different communities of theorists around the quantities of interest to experimentalists, is by now patent. There is by now a community, far wider than the ETSF itself, which has adopted this banner. Several series of conferences, in particular under the auspices of CECAM, now cover different aspects of theoretical spectroscopy, its applications, and different simulation tools. Through it all the ETSF workshop has continued to be a precious opportunity for meeting and discussion within the theoretical spectroscopy community, providing systematic cross-fertilization with all major research groups in the field.The 2012 ETSF workshop will return to the fundamentals of theoretical spectroscopy, providing the in-depth coverage of Green’s function, perturbative, and non-perturbative theories which is necessary to push the field forward. It is thanks to this type of workshop that students receive solid and complete foundations in many-body and excited-state theory, and that experts have the time and opportunity to foster cutting-edge collaborations. ETSF 2012 will address many-body perturbation theory (GW, BSE), time-dependent density functional theory (TDDFT), quantum chemical methods and quantum transport (equilibrium and non-equilibrium). Experts both from within and outside the ETSF will be convened, and sessions will be followed by round-table format discussions, which have proven popular in past editions, and maximize exchange and collaboration.
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 | Improved correlation kernels for linear-response time-dependent density-functional theory
Miquel HUIX I ROTLLANT ,UJF
Date: lundi 19 décembre 2011 14:00
Location: Salle de conférence : Bâtiment André Rassat
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 | From doped semiconductors to pnictides: probing magnetic and superconducting properties with ab init
Lilia Boeri ,Max Planck Institut for Solid State Research, Stuttgart, Germany
Date: 29th November 2011 11:00
Location: Mott D420, Institut Neel, CNRS
Superconductivity, celebrating its 100th anniversary this year, is still at the moment one of the most
exciting fields in condensed matter research. The last ten years have witnessed several discoveries,
extending the domain of known superconductors to intercalated sp systems - MgB2 and CaC6- doped
semiconductors - boron-doped diamond and silicon - and, finally, to a totally new class of two-
dimensional magnetic superconductors, the Fe-pnictide and chalchogenides.
In my talk, I will describe how in all these cases ab-initio calculations have been used to gain a
microscopical view on the nature of the superconducting pairing.
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| # Les Houches school in computational physics: ab initio simulations in condensed matter
Date: 18 -29 June 2012
Location: Les Houches, France
This 10 days school is intended to offer a large panorama of the techniques used in the condensed matter ab initio simulation community. Covering the basics formalisms (DFT, many-body-perturbation-theory, etc.) and their applications (molecular dynamics, vibrational, electronic, optical, or transport properties), formal lectures will be completed by hands-on computer sessions on well distributed packages
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| Daubechies Wavelets in Electronic Structure Calculation: BigDFT Code Tutorial
Date: October 19, 2011 to October 21, 2011
Location: 17 rue du Tour de l'Eau-CampusdeBissy--StMartind'Hères (Grenoble), France
Daubechies wavelets have a number of interesting properties for a basis set being used for electronic structure calculations of complex systems.They form a systematic orthogonal and smooth basis, localized both in real and Fourier space and that allows for adaptivity.Since 2007 the BigDFT code uses this basis for Kohn-Sham Density Functional Theory. The performances of this code meet both the requirements of precision and localization found in many applications.This code may treat traditional and complex environment (e.g. charged systems, electric fields, different boundary conditions...) with a systematic treatment and a mathematically clean description.The formalism is also suitable for state-of-the art high performance computing architectures.The data repartition scheme of the BigDFT code allows to reach optimal efficiency on massively parallel runs.Moreover, in the recent years the Daubechies wavelets formalism has proven useful to benefit from material accelerators (GPU).this code has been the object of the 2009 French Bull-Fourier prize.A hybrid (CPU-GPU) version of the full BigDFT code is available and may benefit of these architectures without reducing the efficiency in parallel runs.
Exploring the benefits of the Daubechies wavelets formalism in the context of electronic structure calculation is thus of great importance either to push state-of-the art approaches to complex environments or to implement novel treatments which may take advantage from the peculiar properties of this basis set.
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| Carbon nanotubes in confined magnetic fields: the anomalous Aharonov-Bohm effect
A. Marini ,Physics department, University of Roma Tor Vergata (Italy)
Date: 01/09/2011 15:00
Location: Sale Mott D420 Batiment D, Institut Neel
2010 celebrated 50 years1 of the Aharonov-Bohm(AB) effect2. Despite the enormous impact that this purely quantistic effect had in different scientific fields the explanation of some high-impact applications remains still grounded to simplified models. One of the most well-known case is given by carbon nanotubes (CNT) that, if immersed in a uniform magnetic field aligned with the tube axis, show peculiar oscillations of the electronic gap. These oscillations are characterized by a period given by the magnetic flux. In the present work we question this picture by showing the results of Ab-Initio simulations carried within the Density Functional Theory scheme. We will discuss, both analytically and numerically, how the AB effect is connected to the geometry of the CNT. We will predict a wealth of novel phenomena connected to the geometry of the magnetic field, to the quantum nature of the electrons and to the CNTs curvature effects. Multi-walled CNTs will be shown to be characterized by a large metallic phase in the low flux regime. If the CNTs are immersed in a uniform (not confined) magnetic field we predict the existence of a trajectory–dependent correction to the AB oscillations due to the electrons spilled out of the CNT surface. This correction is showed to even break the gap periodicity. This is the anomalous Aharonov-Bohm effect.
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| Planetary interiors from a computational perspective
Razvan Caracas ,CNRS, ENS Lyon
Date: JEUDI 23 JUIN 2011 14H30
Location: Institut Néel, Bâtiment F, 3ème étage, Salle F418
Extreme thermodynamic conditions characteristic to the deep interior of the planets are not easy to obtain in the lab. Various experimental devices design to reach these conditions, despite many impressive successes, come with specific limitations. On the other hand numerical techniques, based on atomistic simulations, offer an excellent complementary approach.
Here we analyze some of the major Earth and planetary materials using calculations based on density-functional theory and density-functional perturbation theory. We discuss magnetic transitions under pressure, phase diagrams and element partitioning and we predict high-pressure polymorphs. We also briefly present the WURM project, a freely-available web-based database of computed Raman spectra for minerals and we discuss its applicability in planetary mineralogy.
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| Post-Doc Position on Optical Properties of Nanostructures
Claudio Attaccalite
Date: 01/12/11
Location: Institut Néel, CNRS, Grenoble, France
Post-Doc Position at Institut Néel, CNRS, Grenoble, France
in the \"Theory and Numerical Simulation of Electronic Properties\" group
Subject: \"Ultrafast and non-linear phenomena at the nano-scale\"
Applications are invited for a 1-year postdoctoral position at Institut Néel, in Grenoble, France, to start by January the 1st 2012.
The main role of this position is study optical properties of nanostructure beyond the linear response regime. The goal of this project is to combine out of equilibrium many body theory with density functional theory, in such a way to create a predictive tools to analise and predict non-linear optics and out-equilibrium phenomenas.
The project is funded by SMINGUE-FMN.
The successful applicant will have a strong background in material science or solid state chemistry and physics. Experience in ab-initio calculations and knowledge of Green\'s functions methods would be advantageous.
Applicants should have a Ph.D. in a relevant area of condensed matter physics or materials science.
The closing date for applications is 30 October 2011.
For further details and to apply, please contact: Claudio ATTACCALITE
Email: claudio.attaccalite at cnrs email = grenoble.cnrs.fr
Tel +33-4-76887460
http://www.attaccalite.altervista.org/
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| 16th ESFT Workshop on Electronic Excitations: registration open
Claudio Attaccalite, et al.
Date: 27-30 September 2011
Location: Turin, Italy
The registration for the 16th ETSF Workshop on Electronic Excitations
is now open at http://workshop.etsf.eu
The workshop will be held in Turin from 27 to 30 of September and will point to a
stronger and deeper exchange and dialogue with the community of experimentalists,
besides addressing, as usual, recent methodological advances e.g. in many-body
perturbation theory (GW, BSE), time-dependent density functional theory,
quantum chemical methods or quantum transport. Each section of the workshop will be
dedicated to a kind of spectroscopy and introduced by invited talks from
theory and experiment.
Abstracts will be considered for contributed oral presentations in the appropriate sessions.
Deadline for registration, payment and abstract submission is on the 30th of June.
You can find all practical information at the conference website
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| Strong electronic correlation in hydrogen chains: a Variational Monte Carlo study
Lorenzo STELLA ,Nano-Bio Spectroscopy Group and ETSF, Universidad del País Vasco, San Sebastian Spain
Date: Mardi 5 Avril 15:00
Location: D 420 (3eme étage)
Strong electronic correlation is not properly modelled by Density Functional Theory (DFT) in its current local or semi-local approximations, while explicit many-body techniques, e.g., Dynamical Mean-Field Theory (DMFT) and Quantum Monte Carlo (QMC), have been mostly applied to semiempirical models of strongly correlated extended systems.
In this work, we present an ab-initio Variational Monte Carlo (VMC) study of homogeneous hydrogen chains, which provide a prototypical example of strongly correlated extended systems in one-dimension.
In particular, we have investigated the dependency of some relevant charge- and spin-correlation functions on the interatomic distance to describe the crossover between the weaker and stronger correlated regimes of finite hydrogen chains.
Our VMC findings give valuable analytic insights on the many-body wave function of the chains which can be further used to develop novel DFT functionals for strongly correlated one dimensional systems, both finite and extended.
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| Ionization energies, band gap and electron-phonon coupling in molecular systems within the GW approx
Xavier Blase ,Institut Néel
Date: March 25, 2011 14:00
Location: NanoSTAR seminar, UFR de Chimie, salle de conf. Bât. André Rassat, campus UJF
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| CECAM school: Theoretical Spectroscopy Lectures: Theory and Codes
V. Olevano et al.
Date: May 2-6, 2011
Location: Lausanne, CECAM-HQ-EPFL
Electronic excitations are probed by experimental techniques such as optical absorption, EELS and photo-emission (direct or inverse). From the theory point of view, excitations and excited state properties are out of the reach of density-functional theory (DFT), which is a ground-state theory. In the last twenty years other ab-initio theories and frameworks, which are able to describe electronic excitations and spectroscopy, have become more and more used: time-dependent density-functional theory (TDDFT) and many-body perturbation theory (MBPT) or Green's function theory (GW approximation and Bethe-Salpeter equation BSE). In fact, computational solutions and codes have been developed in order to implement these theories and to provide tools to calculate excited state properties.The present school focuses on these points, covering theoretical, practical, and also numerical aspects of TDDFT and MBPT, and codes implementing them (ABINIT, DP, EXC).
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| 16th ETSF Workshop on Electronic Excitations
Claudio Attaccalite, et al.
Date: 27-30 September 2011
Location: Turin, Italy
The annual ETSF (former NANOQUANTA) Workshop series has developed into an invaluable reference point for the theoretical spectroscopy community. Under the auspices of the European Theoretical Spectroscopy Facility (ETSF) it provides a forum for excited states and spectroscopy in condensed matter physics, chemistry, nanoscience, materials science and molecular physics attracting theoreticians, code developers and experimentalists alike.
The 2011 edition of the workshop will point to a stronger and deeper exchange and dialogue with the community of experimentalists, besides addressing, as usual, recent methodological advances e.g. in many-body perturbation theory (GW, BSE), time-dependent density functional theory (TDDFT), quantum chemical methods or quantum transport.
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| Electronic conductivity of nanotubes and graphene from quantum simulations
Xavier Blase ,Groupe Théorie et Simulation numérique, Institut Néel
Date: Jeudi 27 janvier 2011 16h
Location: Amphithéâtre P015 de l’école PHELMA – Polygone, 23 rue des Martyrs – 38000 Grenoble
Despite the astonishing progresses in our ability to probe experimentally condensed matter systems at the nanometer and femtosecond space and time scales, it remains that probing the atomic and electronic processes in nanosized systems remains a challenge for experiment.
In this context, computer simulations allowing to provide informations about the stability, atomic structure, growth mechanisms, and the electronic, optical and transport properties of molecular systems, have proven very successful in rationalizing, and even predicting, experimental observations.
In this presentation, we will focus on the results of quantum simulations aiming at understanding the conducting properties of nanotubes, nanowires and graphene modified by doping or molecular functionalization. We will discussed in particular one of the problem at the heart of nanoelectronics, namely the difficulty in maintaining good conducting properties of systems with reduced dimensionality.
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| Giant polaronic effects in polymers : breakdown of the electronic picture
Elena Cannuccia ,ETSF and Dept of Physics, University of Rome « Tor Vergata », Italy
Date: Mardi 23 Novembre 2010 11H00
Location: Institut Néel, salle de conf. E. Bertaut, salle F418
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| Wavelet based linear-response time-dependent density-functional theory
Bhaarathi Natarajan ,UJF DCM Grenoble
Date: October 28, 2010 11:15
Location: room N. Mott, bat D, 3eme etage Institut Neel CNRS
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| Hands-on Workshop annoucement: nanoexcite2010
SISSA/CNR-IOM-DEMOCRITOS
Date: 18/10/2010
Location: Trieste
The aim of this hands-on workshop is to introduce advanced concepts of TDDFT, GW and BSE. Short introductory theoretical lectures will be followed by extensive hands-on classes. Participants will have the opportunity of testing on realistic systems the theoretical tools by using several public codes and dedicated tutorials.
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| Many-body gap renormalization in charged silicon nanoclusters
Andrey Titov ,CNRS IM2NP & NEEL. Prokhorov Institute, Russian Academy of Sciences
Date: 09/23/2010 11:00
Location: room N. Mott, bat D, 3eme etage Institut Neel CNRS
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| Time-dependent density-functional theory kernels from many-body perturbation theory
Miquel Huix-Rotllant ,Laboratoire de Chimie Théorique DCM Université J. Fourier
Date: 10/06/2010 11:00
Location: room N. Mott, bat D, 3eme etage Institut Neel CNRS
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| Spectroscopy of La_x Sr_2-x MnO_4 : Cluster Many-Body Calculations and Electronic-Property Study of Related Compounds
Alessandro Mirone ,ESRF Grenoble
Date: 06/05/2010 13:30
Location: salle de conférence, bâtiment André Rassat, campus UJF
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