Sökning: "spin structure"

Visar resultat 1 - 5 av 318 avhandlingar innehållade orden spin structure.

  1. 1. 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

  3. 2. Nanospintronics with Molecular Magnets - Tunneling and Spin-Electric Coupling

    Författare :Javier Francisco Nossa Márquez; Fasta tillståndets fysik; []
    Nyckelord :Molecular magnets; spin exchange; spin-orbit interaction; magnetic anisotropy; spin frustration; spin chirality; spin-electric control; quantum transport; Coulomb blockade; density functional theory; quantum master equation.;

    Sammanfattning : This dissertation investigates theoretically electric control of the magnetic properties of molecular magnets. Two classes of magnetic molecules are considered. The first class consists of molecules that are spin frustrated. LÄS MER

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

    Författare :Masoumeh Fazlali; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; 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

  5. 4. Spin ice and demagnetising theory

    Författare :Mikael Twengström; Patrik Henelius; Peter Holdsworth; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Geometrical frustration; spin ice; Monte Carlo simulations; demagnetising theory; special temperatures; Ewald summation; neutron scattering; structure factors; loop algorithms; parallel tempering; frustrated ferromagnets; equilibration issues; long-range interactions; exchange interactions.; Fysik; Physics;

    Sammanfattning : Frustration, or the inability to simultaneously minimise all local interactions is, a phenomenon occurring in a broad number of physical systems. We will in this thesis focus on a class of frustrated ferromagnetic materials called spin ices and how both numerical and experimental techniques can be used to understand their properties. LÄS MER

  7. 5. Theoretical Studies of Spin-Dependent Quantum Phenomena in Semiconductor Nanostructures

    Författare :Patrik Brusheim; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Zitterbewegung.; spin Hall effect; spintronics; Spin; quantum transport;

    Sammanfattning : The study of spin transport has emerged at the forefront of condensed matter physics during the last decade. Much of the interest has undoubtedly been sparked by the advent of the spintronics paradigm and the idea of creating novel electronic devices based on the spin degree of freedom of the carriers. LÄS MER