toward coherent ultrafast transmission electron microscopy
Contents
1. Proposition de sujet de these Septembre 2015 TOWARD COHERENT ULTRAFAST TRANSMISSION ELECTRON MICROSCOPY Funding Type Bourse MESR Priority of CEMES CNRS Keywords ultrafast Transmission Electron Microscopy nano optics ultrafast dynamics Scientific supervisors Arnaud ARBOUET amp Florent HOUDELLIER Laboratory CEMES CNRS UPR8011 Toulouse Collaborations Laboratoire de Physique des Solides Mathieu Kociak Application deadline J uly 2015 interested candidates are strongly encouraged to contact us as soon as possible CONTEXT Investigation of the physics of nanostructures requires nanometer or atomic Spatial resolution meV spectral resolution and femto to nanosecond time resolution Accessing all these informations simultaneously would be a breakthrough in nanophysics However up to now no technique offers this unique combination of performances Ultrafast Transmission Electron Microscopes UTEM combining sub picosecond temporal resolution and nanometer spatial resolution have very recently emerged as unique tools for investigations at both ultimate spatial and temporal resolutions However the performances of state of the art UTEM are in practice limitating the spatial resolution to tens to hundreds of nanometers unfortunately larger than the lengthscale of most of the relevant nanophysics phenomena ABSTRACT The FemTOTEM project aims at developing an alternative Ultrafast Transmission Electron Microscope based o2. n a high brightness laser driven field emission electron source working under 200kV acceleration voltage The latter consists of a metallic nanotip illuminated by femtosecond laser pulses This development will be achieved by bringing together a femtosecond laser source and a customized 200kV cold field emission Transmission Electron Microscope CFE TEM This unique combination of femtosecond time resolution and high brightness allowing an optimization between probe current and spatial coherence will have an unrivalled potential for frontier research in nanophysics and fundamental science This development will enable fast electron based nanospectroscopies and lead to the first time resolved electron holography experiments Its 4 major objectives are e Picosecond Time Resolved Cathodoluminescence pTRCL studies of the carrier dynamics in semi conductor nanostructures at the nanometer scale e Electron Energy Gain Spectroscopy EEGS of plasmonic and photonic nanosystems Proposition de sujet de these Septembre 2015 e Ultrafast electron holography e Ultrafast electron diffraction This project is mostly experimental The first objective of this thesis is the finalization of the development of the ultrafast Transmission Electron Microscope and the complete characterization of its performances probe current brightness spatial spectral and temporal resolutions The second objective is the demonstration of its potential first on routine s
3. tatic electron microscopy experiments and then on the new experiments listed above First Cathodoluminescence experiments will be performed on semiconductor nanostructures to investigate the electron dynamics in quantum confined nanostructures with nanometer scale resolution Second Electron Energy Gain spectroscopy will be used to gain insight into the properties of plasmonic and photonic nanostructures at ultimate spatial and spectral resolution Finally the last objective of this thesis is the realization of ultrafast electron holography experiments An important part of this thesis will also be dedicated to the modeling of various aspects of the experiments involving optical excitation and ultrashort electron pulses generation propagation and characterization of ultrashort electron pulses interaction of ultrashort electron pulses with an optically excited nano object Candidate Profile The PhD candidate should have a Master s degree or comparable in physics solid state physics optics nonlinear optics or quantum mechanics He she will also have a taste for demanding experiments It is requested to provide a detailed CV with any application Contacts arbouet cemes fr florent cemes fr Funding of the project ANR FemtoTEM 2015 2019 N ANR 14 CE26 0013 01
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