Sökning: "Spin transfer torque"

Visar resultat 1 - 5 av 15 avhandlingar innehållade orden Spin transfer torque.

  1. 1. Magnetization Dynamics in Nano-Contact Spin Torque Oscillators : Solitonic bullets and propagating spin waves

    Författare :Stefano Bonetti; Johan Åkerman; Thomas Silva; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; magnetism; spintronics; thin magnetic films; spin transfer torque; magnetization dynamics; spin waves; microwave oscillators; giant magneto-resistance; Magnetism; Magnetism;

    Sammanfattning : Magnetization dynamics in nano-contact spin torque oscillators (STOs) is investigated from an experimental and theoretical point of view. The fundamentals of magnetization dynamics due to spin transfer torque are given. A custom-made high frequency (up to 46 GHz) in large magnetic fields (up to 2. LÄS MER

  2. 2. Fabrication and Characterization of Nanocontact Spin-Torque Oscillators

    Författare :Sohrab Redjai Sani; Johan Åkerman; Brad Engel; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Spin-torque oscillators; phase locking; spin wave; giant magnetoresistance; spin transfer torque; thin films.;

    Sammanfattning : The manufacturing of nanocontact-based spin-torque oscillators (NC-STOs)has opened the door for spintronic devices to play a part as active microwaveelements. The NC-STO has the capability of converting a direct current intoa microwave signal, and vice versa, by utilizing the spin transfer torque (STT)in ferromagnetic multilayer systems. LÄS MER

  3. 3. Magnetodynamics of pseudo spin valves investigated using co-planar waveguide and spin torque ferromagnetic resonance techniques

    Författare :Masoumeh Fazlali; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :Spintronics; Nanocontact pseudo spin valve; Spin waves; Oersted field; Interlayer exchange coupling; Acoustic and optical modes; Spin pumping; Spin transfer torque; Slonczewski mode; Collective mode;

    Sammanfattning : Nanocontact spin-torque nano-oscillators (NC-STNOs), based on magnetic multilayers, can generate a wide range of highly nonlinear localized and propagating spin wave modes for use in magnonics. In this thesis, we study some aspects of these structures from the fundamental physics point of view using the spin torque ferromagnetic resonance technique (ST-FMR) and conventional broadband FMR technique. LÄS MER

  4. 4. Spin Dynamics and Magnetic Multilayers

    Författare :Björn Skubic; Olle Eriksson; Lars Nordström; Mark D. Stiles; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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. 5. Theory of X-ray Absorption Spectra and Spin Transfer Torque

    Författare :Ola Wessely; Olle Eriksson; Lars Nordström; Eric Shirley; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Physics; First principles calculations; X-ray absorption spectroscopy; Carbon nanotubes; Helical spin density waves; Hydrogen storage; Spin transfer torque; Fysik; Physics; Fysik;

    Sammanfattning : The subjects of the thesis are theoretical first principles calculations of X-ray absorption (XA) spectra and current induced spin transfer torque. XA spectra calculated from atomic multiplet theory and from band structure calculations, based on density functional theory for La0.7Sr0.3MnO3 have been compared to experiment. LÄS MER