Sökning: "ultrafast magnetism"

Visar resultat 6 - 10 av 13 avhandlingar innehållade orden ultrafast magnetism.

  1. 6. Terahertz spin dynamics in metallic thin film ferromagnets

    Författare :Kumar Neeraj; Stefano Bonetti; Andreas Rydh; Michael Farle; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Terahertz; ultrafast magnetism; spin dynamics; spin nutation; magnetization switching; fysik; Physics;

    Sammanfattning : The past two decades have witnessed an increasing interest in understanding and controlling materials at the pico- and femtosecond time scales, the so-called ultrafast regime. Among the broad field of condensed matter physics, magnetism and magnetic materials have attracted much interest both from a fundamental and an applied perspective. LÄS MER

  3. 7. Atomistic Spin Dynamics, Theory and Applications

    Författare :Johan Hellsvik; Olle Eriksson; Lars Nordström; Ulrich Nowak; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ab initio calculations; spin dynamics; magnetization; magnetic switching; diluted magnetic semiconductors; spin glasses; ferromagnetic relaxation; ferrimagnets; antiferromagnets; Magnetism; Magnetism; Condensed matter physics; Kondenserade materiens fysik; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : The topic of this Thesis is magnetization dynamics on atomic length scales. A computational scheme, Atomistic Spin Dynamics, based on density functional theory, the adiabatic approximation and the atomic moment approximation is presented. LÄS MER

  4. 8. Spin Dynamics and Magnetic Multilayers

    Författare :Björn Skubic; Olle Eriksson; Lars Nordström; Mark D. Stiles; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; magnetism; electronic structure; density functional theory; spin dynamics; spin-transfer torque; spin-density wave; multilayer; interface structure; Fysik;

    Sammanfattning : Theoretical studies based on first-principles theory are presented for a number of different magnetic systems. The first part of the thesis concerns spin dynamics and the second part concerns properties of magnetic multilayers. The theoretical treatment is based on electronic structure calculations performed by means of density functional theory. LÄS MER

  5. 9. Amorphous and crystalline functional materials from first principles

    Författare :Leyla Isaeva; Olle Eriksson; Jörg Neugebauer; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; first-principles theory; lattice dynamics; phase transitions; amorphous materials; tribology; ultrafast magnetism;

    Sammanfattning : This thesis deals with various functional materials from first-principles methods and is divided into two major parts according to the underlying atomic structure of the system under study. The first part of the thesis deals with the temperature-induced structural phase transitions in metallic  β'-AuZn and perovskite oxide LiOsO3. LÄS MER

  7. 10. 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