Sökning: "XY-type models"

Hittade 2 avhandlingar innehållade orden XY-type models.

  1. 1. Characteristic properties of two-dimensional superconductors close to the phase transition in zero magnetic field

    Författare :Kateryna Medvedyeva; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; superconductor; two dimensions; phase transition; vortex; currentvoltage characteristics; complex conductivity; scaling; critical exponents; XY-type models; dynamics; Physics; Fysik; fysik; Physics;

    Sammanfattning : The main focus of this thesis lies on the critical properties of twodimensional (2D) superconductors in zero magnetic field. Simulations based on variants of the 2D XY model are shown to give characteristic features close to the phase transition which agree qualitatively with experimental data. LÄS MER

  3. 2. Vortex fluctuations in superconductors

    Författare :Peter Olsson; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Superconductor; Two dimensions; vortex; coulomb gas; XY model; Kosterlitz-Thouless transition; high-Tc.;

    Sammanfattning : The vortex fluctuations have proved to be responsible for the onset of dissipation in thin type-II superconducting Aims. There is also growing evidence that dissipation in high- temperature superconductors exhibits the same kind of two-dimensional (2D) behavior. LÄS MER