Sökning: "Electron-phonon interaction"

Visar resultat 1 - 5 av 17 avhandlingar innehållade orden Electron-phonon interaction.

  1. 1. Electron-Phonon Interactions in Transition Metal Oxides Studied by Resonance Raman Scattering

    Författare :Jakob Andreasson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Franck-Condon; Fr ohlich interaction; higher order scattering; perovskite; transition metal oxide; two-phonon; oxygen breathing mode; Raman spectroscopy;

    Sammanfattning : In this thesis, studies of strong electron-phonon interactions in a number of transition metal oxides are presented. Two different electron-phonon interaction mechanisms are identified; Franck-Condon scattering and infrared active longitudinal optical (IR LO) two-phonon activation. LÄS MER

  3. 2. MgB2 hot-electron bolometer mixers for sub-mm wave astronomy

    Författare :Evgenii Novoselov; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; hot-electron bolometer; gain bandwidth; noise bandwidth; thin film; electron-phonon interaction; noise temperature; THz detector; conversion gain; mixer; magnesium diboride; superconductor;

    Sammanfattning : Spectroscopy and photometry in the terahertz (THz) range of remote space objects allows for a study of their chemical composition, because this range covers rotational lines from simple molecules and electron transition lines from atoms and ions. Due to high spectral resolution, THz heterodyne receivers al- low for studying dynamical properties of space objects manifested in doppler-shifted emission lines. LÄS MER

  4. 3. Theoretical studies of lattice- and spin-polarons

    Författare :Nina Bondarenko; Olle Eriksson; Natalia Skorodumova; Manuel Pereiro; Maria Roser Valenti Vall; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Polaron; Nonlinear Schrödinger Equation; Nonlocality; Solitons; Integrable systems; Quantum field theory low energy ; Electron-phonon interaction; Density functional theory; Electronic structure of atoms and molecules; Spin-polaron; Langevin equation; Transport properties; Hubbard model; Heisenberg lattice; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : Theoretical studies of lattice- and spin-polarons are presented in this thesis, where the primary tool is ab-initio electronic structure calculations. The studies are performed with employment of a variety of analytical and computational methods. LÄS MER

  5. 4. Tight-binding calculations of electron scattering rates in semiconducting zigzag carbon nanotubes

    Författare :Kannan Thiagarajan; Ulf Lindefelt; Hans-Erik Nilsson; Sven Öberg; Mittuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tight-binding; carbon nanotubes; electron-phonon scattering; backscattering; forward scattering; Semiconductor physics; Halvledarfysik;

    Sammanfattning : The technological interest in a material depends very much on its electrical, magnetic, optical and/or mechanical properties. In carbon nanotubes the atoms form a cylindrical structure with a diameter of the order 1 nm, but the nanotubes can be up to several hundred micrometers in length. LÄS MER

  7. 5. Theoretical Description of the Electron-Lattice Interaction in Molecular and Magnetic Crystals

    Författare :Elham Mozafari; Igor A. Abrikosov; Sven Stafström; George Malcolm Stocks; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Molecular crystals; Charge transport; Polaron; Magnetic materials; Paramagnetic state; Molecular dynamics;

    Sammanfattning : Electron-lattice interactions are often considered not to play a major role in material's properties as they are assumed to be small, the second-order effects. However, this study shows the importance of taking these effects into account in the simulations. LÄS MER