Search for dissertations about: "RKKY"

Showing result 1 - 5 of 7 swedish dissertations containing the word RKKY.

  2. 1. Probing Magnetism at the Atomic Scale:  Non-Equilibrium Statistical Mechanics Theoretical Treatise

    Author : Juan David Vasquez Jaramillo; Jonas Fransson; Rosa Lopez; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Non-Equilibrium Statistical Mechanics; Magnetism; Quantum Optics; Quantum Coherence; RKKY; Colciencias; Equation of Motion; Jauho-Meir-Wingreen Formalism; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik; Physics with specialization in Quantum Chemistry; Fysik med inriktning mot kvantkemi; Physics and Astronomy specializing in Theoretical Physics; Fysik och astronomi med inriktning mot teoretisk fysik;

    Abstract : Here, I present a theoretical study, based on non-equilibrium quantum statistical mechanics and on the non-equilibrium extension to the RKKY intveraction,where I investigate the emergence of magnetism at the atomic scale in adsorbed molecular complexes hosting localized spin moments, at the stake of being probed with scanning tunneling microscopy tip, and being driven by a temperature gradient and gated by an electric field. The scanning tunneling microscopy set up is modeled as a molecular junction with a magnetic molecule embedded within it, where the molecule consists in a set of electronic levels resembling the typical s-p orbitals of a metal hydride or an organometal, and a localized spin moment resembling the magnetic unit hosted by the latter and former type of molecules mentioned. READ MORE

  4. 2. Spin Vortices, Interlayer Exchange, and Magnetocalorics in Multilayers

    Author : Milton Persson; Vladislav Korenivski; David B. Haviland; Coriolan Tiusan; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Spin vortex pairs; bimerons; RKKY; finite size effects; nanostructure magnetocalorics; atomistic spin dynamics; nanocalorimetry; Spinvirvelpar; bimeron; RKKY; finita storlekseffekter; magnetkalorimetri i nanostrukturer; atomistisk spindynamik; nanokalorimetri; Material and Nano Physics; Material- och nanofysik;

    Abstract : In this thesis we study strongly coupled pairs of spin vortices, in a configurationsuch that the cores attract while external fields act to pull them apart, with potential applications in magnetic random access memory (MRAM) and oscillators.Inertial decoupling of the cores has been studied and can be achieved with weak nanosecond pulses by the help of anharmonicity. READ MORE

  5. 3. Resonant vortex-pair dynamics and magnetocalorics in magnetic nanostructures

    Author : Erik Holmgren; Vladislav Korenivski; Gisela Schütz; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik;

    Abstract : This thesis investigates the dynamics of spin vortex pairs in nanopillars andthermal effects in magnetic multilayers with RKKY-like indirect exchange.Spin vortices are being investigated as storage elements for memory applicationsas well as for GHz oscillators and signal processing devices. READ MORE

  6. 4. Internal magnetic properties in rare earth metals and compounds

    Author : Mikael Ekström; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik; fysik; Physics;

    Abstract : In gadolinium the pressure dependence of the local field has been studied. Applied field up to 0.6 GPa have a very strong influence on the local muon fields. READ MORE

  7. 5. Frustrated magnetism in icosahedral structures : The influence of order-disorder in quasicrystals and approximant crystals

    Author : Fernand Denoel; Roland Mathieu; Marc de Boissieu; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quasicrystals; approximant crystals; spin glasses; SQUID magnetometry; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : This work will begin with an introduction to quasicrystals (QCs) and their structure, defining the unit cell-equivalent for icosahedral quasiperiodicity: a 3D tiling based on the golden ratio and aperiodic in all three dimensions. We briefly present the cut-and-project method used to generate QCs from a higher dimension hypercrystal, and how to build the 3D Penrose tilings, composed of the two golden rhombohedra. READ MORE