Sökning: "Vortices"

Visar resultat 1 - 5 av 156 avhandlingar innehållade ordet Vortices.

  1. 1. Singular Ginzburg-Landau Vortices

    Författare :Mats Aigner; Matematik (naturvetenskapliga fakulteten); []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; singularities; Ginzburg-Landau; vortices; Matematik;

    Sammanfattning : In this thesis we study the critical Ginzburg-Landau action, defined on fields in the plane which are allowed to have a finite number of singularities. We show that a topological invariant, the degree, can be defined under the assumption of finite action only. LÄS MER

  3. 2. Vortices and Persistent Currents in Rotating Bose Gases - a Diagonalization Approach

    Författare :Sara Bargi; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Bose-Einstein condensation; vortices; superfluidity; Fysicumarkivet A:2010:Bargi;

    Sammanfattning : In this thesis, I explore the behavior of rotating ultra-cold Bose gases, by diagonalizing the Hamiltonian. This method has the advantage of being exact in the limit of weak interactions, and thus is a useful complement to the more commonly used Gross-Pitaevskii (GP) equation, which relies on a mean-field approximation. LÄS MER

  4. 3. From exotic superconductivity to QCD and back again searching things in common

    Författare :Egor Babaev; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical physics; Chrial symmetry; Pseudogap; vortices; knots; solitons; Teoretisk fysik; Physics; Fysik;

    Sammanfattning : This thesis is devoted largely to two new features which Particle Physics and Condensed Matter theory have in common. The first part of the thesis is a discussion of formation of phases precursory to the chiral phase transition in relativistic models with four-fermion interactions, considered as toy models for QCD. LÄS MER

  5. 4. Phase transitions in high-temperature superconductors

    Författare :Jack Lidmar; KTH; []
    Nyckelord :Superconductivity; Vortices; Phase transitions; Strongly correlated fermions; High-temperature superconductivity; Monte Carlo simulations.; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : Thermal fluctuations and disorder strongly influence the behaviour of hightemperature superconductors. In particular the vortices play a key role in determining their properties. In this thesis the main focus lies on phase transitions, both in ultra-thin films and in three-dimensional systems, which are driven by vortex fluctuations. LÄS MER

  7. 5. Phase transitions and vortex structures in multicomponent superconductors

    Författare :Karl Sellin; Egor Babaev; Astrid S. de Wijn; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; multicomponent superconductors; superconductivity; phase transitions; monte carlo; vortices; vortex structure formation; competing interactions;

    Sammanfattning : Theoretical aspects of multicomponent superconductivity and systemswith competing interactions are studied using Monte Carlo techniques.Motivated by recent experimental and theoretical results of complex struc-ture formation of vortices in multicomponent systems, possible vortex struc-ture formations due to vortex interactions that are not purely attractive orrepulsive are considered. LÄS MER