Sökning: "spin spirals"

Hittade 4 avhandlingar innehållade orden spin spirals.

  1. 1. Non-collinear Magnetism in d- and f-electron Systems

    Författare :Raquel Lizárraga Jurado; Olle Eriksson; Lars Nordström; Axel Svane; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Non-collinear magnetism; spin spirals; first principles; density functional theory; Fermi surfaces; electronic structure; f-electron systems; Fysik;

    Sammanfattning : In this thesis, non-collinear magnetism has been studied by using density functional theory and the augmented plane wave method with local orbitals (APW+lo). Two conditions for non-collinear instabilities have been identified in this thesis. First, the Fermi energy should cut through both spin up and down states. LÄS MER

  3. 2. Ab initio Studies on Exchange Interactions in Metals and Correlated Oxides

    Författare :Adam Jakobsson; Biplab Sanyal; Marjana Lezaic; Nicola Spaldin; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : A report is given on the implementation of a frozen magnon technique in the FLAPW code FLEUR, showing that the procedure reduced computational costs compared with a previously implemented method, while delivering accurate results. Furthermore a generalisation was made of the well known one lattice formula that connects the total energy differences of spin-spirals to the adiabatic magnon excitation energies to multiple lattice systems. LÄS MER

  4. 3. Materials Design from First Principles : stability and magnetism of nanolaminates

    Författare :Martin Dahlqvist; Johanna Rosén; Nicola Spaldin; Linköpings universitet; []
    Nyckelord :;

    Sammanfattning : In this thesis, first-principles calculations within density functional theory are presented, with a principal goal to investigate the phase stability of so called Mn+1AXn (MAX) phases. MAX phases are a group of nanolaminated materials comprised of a transition metal (M), a group 12-16 element (A), and carbon or nitrogen (X). LÄS MER

  5. 4. Novel Phenomena in Superconductors and Superfluids: Boundary States, Spiral Magnetic Fields, and Solitons

    Författare :Albert Samoilenka; Egor Babaev; Max Metlitskii; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical Physics; Teoretisk fysik;

    Sammanfattning : This PhD thesis presents a comprehensive study of superconducting and superfluid states in a variety of physical systems.The research is based on 12 papers that explore different phenomena in-depth.One of the significant contributions of the thesis is the discovery of boundary states in superconductors. LÄS MER