Sökning: "fast electron dynamics"

Visar resultat 1 - 5 av 44 avhandlingar innehållade orden fast electron dynamics.

  1. 1. Ultrafast spin, lattice, and electron dynamics in thin metallic films : in the terahertz, near-infrared, and extreme ultraviolet regimes

    Författare :Vivek Unikandanunni; Stefano Bonetti; Andreas Rydh; Jurgen Lindner; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Terahertz; near-infrared; extreme ultraviolet; epitaxial cobalt; transient grating; field emission; gold; platinum; electron-phonon coupling; magneto-crystalline anisotropy; nanoscale dynamics; ultrafast spin dynamics; magnetic inertia; nutation; pump-probe; two-temperature model; Fowler-Nordheim tunneling; fysik; Physics;

    Sammanfattning : In this thesis, we studied the ultrafast spin and electron dynamics triggered by electromagnetic radiation belonging to three different regions of the electromagnetic spectrum, namely terahertz, near-infrared and extreme ultraviolet. By performing pump–probe measurements, we explored the role of the lattice in ultrafast spin and electron dynamics in metallic thin films. LÄS MER

  3. 2. Dissociation dynamics of highly excited molecules: Theory and Experiment

    Författare :Shabnam Oghbaie; Synkrotronljusfysik; []
    Nyckelord :Molecular dissociation; core-electron excitation; double ionization; femtoseconds molecular dynamics; Isomerization; symmetry breaking; momentum imaging; site-selective dissociation; butadiene; cyclopropane; nuclear dynamics; Auger decay;

    Sammanfattning : This thesis presents studies on dissociation of two model molecules: Butadiene and Cyclopropane. Tunable synchrotron radiation was used to ionize or excite the molecules in the gas phase, and the momentum correlation of the resulting fragment ions were measured using a 3D momenta coincident ion spectroscopy. LÄS MER

  4. 3. Fast dynamics and measurements of single-charge devices

    Författare :Fredrik Persson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; resonator; single-electron box; superconducting devices; decoherence; quantum capacitance; Sisyphus resistance; transmon; single-Cooper-pair box; qubit; rf-reflectometry;

    Sammanfattning : In this thesis we present measurements on several different devices, including the single-Cooper-pair box (SCB), the single-electron box, tunable superconducting resonators and so called transmon qubits.By exploiting the quantum capacitance of the SCB, its state was measured by embedding the box in a radio-frequency resonator. LÄS MER

  5. 4. Model Studies of Electron Transfer and Reaction Dynamics at Surfaces

    Författare :Johan Strömquist; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; dissociation; desorption; oxidation; hot precursors; surface chemical reaction; chemiluminescence; surface harpooning; charge transfer; electron emission; transient mobility; non-adiabaticity;

    Sammanfattning : Charge-transfer is of key importance in many physical, chemical and biological processes, including surface reactions. This thesis consists of several theories for and model studies of surface reactions that are initiated by electron transfer between the surface to a molecule. LÄS MER

  7. 5. Kinetic modeling of runaway-electron dynamics in partially ionized plasmas

    Författare :Linnea Hesslow; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; runaway electrons; tokamaks; plasma physics; magnetic confinement fusion; electron-ion collisions; Fokker-Planck equation;

    Sammanfattning : An essential result of kinetic plasma physics is the runaway phenomenon, whereby a fraction of an electron population can be accelerated to relativistic energies. Such runaway electrons are formed in astrophysical settings, but are also of great practical relevance to fusion research. LÄS MER