Sökning: "spin modellen"

Visar resultat 1 - 5 av 20 uppsatser innehållade orden spin modellen.

  1. 1. Spin-Glass Behaviour in Ordered Solids

    Kandidat-uppsats, Uppsala universitet/Materialteori

    Författare :Erik Karpelin; [2023]
    Nyckelord :spin-glass; self-induced; variation; Edwards-Andersson; glassy;

    Sammanfattning : The spin-glass is a peculiar magnetic phase, exhibiting non-trivial dynamics at low temperatures, characterized by an continuously evolving state without long-range order. The behavior requires some degree of disorder to occur, often in the way of impurities or random exchange energy between the spins. LÄS MER

  2. 2. Investigation of a newrepresentation of spin

    Kandidat-uppsats, Uppsala universitet/Materialteori

    Författare :Minna Palmgren Thun; [2023]
    Nyckelord :Material theory; Spin; Statistical physics; Second quantization; Materialteori; spinn;

    Sammanfattning : The Bose-Hubbard Model, a tight binding model within solid state theory can be solved exactly using a number theoretical approach. From this approach, in the two sited Bose-Hubbard model, the hopping term in the model takes the form of a Pauli x matrix. The hopping term can be interpreted as a two energy level system or a dimer with k+1 particles. LÄS MER

  3. 3. Exact eigenstates of the Inozemtsev spin chain

    Master-uppsats, KTH/Fysik

    Författare :Simon Lentz; [2021]
    Nyckelord :Theoretical physics; Mathematical physics; quantum mechanics; many-body problems; spin chain; Inozemtsev; Calogero-Sutherland; Teoretisk fysik; Matematisk fysik; kvantmekanik; mångpartikel problem; spinnkedjor; Inozemtsev; Calogero-Sutherland;

    Sammanfattning : This thesis deals with the following question: are there more eigenfunctions, other than the already known eigenfunctions, of the spin chain with elliptic interactions known as the Inozemtsev spin chain? The Inozemtsev spin chain interpolates between two quantum integrable spin chains, theHeisenberg spin chain and the Haldane-Shastry spin chain. Therefore it is interesting to explore eigenfunctions of the Inozemtsev spin chain in greater detail. LÄS MER

  4. 4. Phase Diagrams of Finite Spin Chains with Coupled Spin and Lattice Vibrations

    Kandidat-uppsats, Uppsala universitet/Materialteori

    Författare :Siri Alva Berge; [2021]
    Nyckelord :spin-lattice coupling; spin-vibration coupling; Heisenberg exchange; magnetism;

    Sammanfattning : The spin-lattice coupling is due to itinerant electrons interacting with both spins of ions and phonons, mediating a coupling between magnetic spin moments and lattice vibrations. In this project, the coupling is studied systematically for finite quantum spin chains of size 2 – 10. LÄS MER

  5. 5. Topological properties of flat bands in generalized Kagome lattice materials

    Master-uppsats, KTH/Fysik

    Författare :Daniela Pinto Dias; [2021]
    Nyckelord :tight-binding; topological insulators; flat bands; edge states; honeycomb-Kagome lattice; tätt bindande modell; topologiska isolatorer; platta band; kanttillstånder; bikakan-Kagome gitter;

    Sammanfattning : Topological insulators are electronic materials that behave like an ordinary insulator in their bulk but have robust conducting states on their edge. Besides, in some materials the band structure presents completely flat bands, a special feature leading to strong interactions effects. LÄS MER