Search for dissertations about: "lattice dynamics"

Showing result 11 - 15 of 93 swedish dissertations containing the words lattice dynamics.

  1. 11. Atomistic Spin Dynamics, Theory and Applications

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Johan Hellsvik; Uppsala universitet.; [2010]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ab initio calculations; spin dynamics; magnetization; magnetic switching; diluted magnetic semiconductors; spin glasses; ferromagnetic relaxation; ferrimagnets; antiferromagnets; NATURAL SCIENCES Physics Condensed matter physics Magnetism; NATURVETENSKAP Fysik Kondenserade materiens fysik Magnetism; NATURAL SCIENCES Physics Condensed matter physics; NATURVETENSKAP Fysik Kondenserade materiens fysik; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : 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. READ MORE

  2. 12. Interacting particle systems for opinion dynamics: the Deffuant model and some generalizations

    University dissertation from Göteborg : Chalmers University of Technology

    Author : Timo Hirscher; Göteborgs universitet.; Gothenburg University.; [2016]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Deffuant model; bounded confidence; opinion dynamics; sociophysics; consensus formation; general opinion space; percolation; pumpless water transport.;

    Abstract : In the field of sociophysics, concepts and techniques taken from statistical physics are used to model and investigate some social and political behavior of a large group of humans: their social network is given by a simple graph and neighboring individuals meet and interact in pairs or small groups. Although most of the established models feature rather simple microscopic interaction rules, the macroscopic long-time behavior of the collective often eludes an analytical treatment due to the complexity, which stems from the interaction of the large system as a whole. READ MORE

  3. 13. Theoretical studies of lattice- and spin-polarons

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Nina Bondarenko; Uppsala universitet.; [2018]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Polaron; Nonlinear Schrödinger Equation; Nonlocality; Solitons; Integrable systems; Quantum field theory low energy ; Electron-phonon interaction; Density functional theory; Electronic structure of atoms and molecules; Spin-polaron; Langevin equation; Transport properties; Hubbard model; Heisenberg lattice; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : Theoretical studies of lattice- and spin-polarons are presented in this thesis, where the primary tool is ab-initio electronic structure calculations. The studies are performed with employment of a variety of analytical and computational methods. READ MORE

  4. 14. Water Relaxation Processes as Seen by NMR Spectroscopy Using MD and BD Simulations

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Ken Åman; Umeå universitet.; [2005]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physical chemistry; NMR; Stochastic Liouville Equation; Brownian Dynamics; Molecular Dynamics; Water; Relaxation; Deuterium; ESR; Fysikalisk kemi; NATURAL SCIENCES Chemistry Physical chemistry; NATURVETENSKAP Kemi Fysikalisk kemi; Physical Chemistry; fysikalisk kemi;

    Abstract : This thesis describes water proton and deuterium relaxation processes, as seen by Nuclear Magnetic Resonance (NMR) spectroscopy, using Brownian Dynamics (BD) or Molecular Dynamics (MD) simulations. The MD simulations reveal new detailed information about the dynamics and order of water molecules outside of a lipid bilayer. READ MORE

  5. 15. Optical Spectroscopy on Correlated Electron Materials

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Johan Bielecki; [2010]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; dynamics; optical spectroscopy; colossal magnetoresistance; magnetism; transition metal oxides; high temperature superconductivity;

    Abstract : Strongly correlated materials poses a great challenge to our microscopic understanding of matter, mainly due to the inability of perturbative methods to predict the properties of such materials. This inability stems from strong correlations between electronic, lattice and spin degrees of freedom, leading to a variety of complex and exotic phenomena such as (unconventional) superconductivity, metal-insulator transitions, non-Fermi liquid behavior and colossal magnetoresistance. READ MORE