Sökning: "XY-modell"

Hittade 3 uppsatser innehållade ordet XY-modell.

  1. 1. Numerical Estimation of Critical Exponents in the 3D XY Model

    Master-uppsats, KTH/Fysik

    Författare :Christoffer Beiming; [2023]
    Nyckelord :Theoretical physics; Condensed matter theory; Phase transitions; XY model; Critical exponents; Computational physics; Monte Carlo simulations; Teoretisk fysik; Kondenserade materiens teori; Fasövergångar; XY-modellen; Kritiska exponenter; Beräkningsfysik; Monte Carlo simulering;

    Sammanfattning : The experimentally obtained value of the critical exponent ν is presently in significant disagreement with current theoretical predictions for the λ-universality class. We suggest two novel approaches of determining the exponents ν and η by utilizing the effects of finite size scaling. LÄS MER

  3. 2. Effects of power-law correlated disorder on a 3D XY model

    Master-uppsats, KTH/Fysik

    Författare :Philip Broms; [2022]
    Nyckelord :Condensed matter physics; Ising model; XY model; Markov Chain Monte Carlo; Phase transition; Disorder; Theoretical physics; Wolff algorithm; Kondenserade materians teori; Isingmodell; XY-modell; Markovkedje-Monte Carlo-metoder; Teoretisk fysik; Oordning; Fasövergångar; Wolffalgoritmen;

    Sammanfattning : This thesis investigates the effects of power-law correlated disorder on a three-dimensional XY model and the Weinrib-Halperin disorder relevance criterion’s pre-dictive ability. Ising models are used as a map to realise disorder couplings. LÄS MER

  4. 3. Models of superconductors with correlated defects

    Master-uppsats, KTH/Fysik

    Författare :Jakob Bolin; [2022]
    Nyckelord :Quantum phase transition; correlated disorder; 3D XY model; Monte Carlo simulation; worm algorithm; winding number; superfluid density; Kvantfasövergång; korrelerad oordning; 3D XY modell; Monte Carlo simulering; worm algoritmen; vindlingstal; supraledande täthet;

    Sammanfattning : The quantum phase transition between groundstates of a system with correlated disorder near absolute zero is studied. The computations are based on Monte Carlo methods and the worm algorithm which is an effective method to simulate basic models like the Ising and XY model by making use of global Monte Carlo moves given by modified random walks. LÄS MER