Sökning: "Heisenberg exchange"

Visar resultat 1 - 5 av 7 uppsatser innehållade orden Heisenberg exchange.

  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

  3. 2. Revival structure of the residual entanglement in a three-qubit system

    Kandidat-uppsats,

    Författare :Carl Agelii; Rasmus Andersson; William Bakke Lindblom; [2023]
    Nyckelord :qubit; tripartite entanglement; residual entanglement; antisymmetric exchange; Quantum Heisenberg model;

    Sammanfattning : The quantum mechanical phenomenon of entanglement plays a key role in areas such as quantum computing and quantum information. Entangled half spin particles, often called qubits, are used to realize quantum based logic which means that studying systems of qubits and their properties is of vital importance to the development of the fields. LÄS MER

  4. 3. Comparing Quantum and Semi-Classical Approaches to Non-Collinear Magnetism in an Electron-Spin Dimer

    Kandidat-uppsats, Lunds universitet/Fysiska institutionen; Lunds universitet/Matematisk fysik

    Författare :Sherwan Jamo Abdi; [2023]
    Nyckelord :Skyrmion Electron Spin Dzyaloshinskii-Moriya Interaction DMI Ehrenfest Semiclassical; Physics and Astronomy;

    Sammanfattning : In this bachelor thesis, an explorative theoretical analysis is presented on a model system characterized by various and competing magnetic interactions. The system comprises two localized magnetic moments (spins), and a single itinerant electron that hops between two orbitals located at the spins’ positions. LÄS MER

  5. 4. Quantum Landau-Lifshitz-Gilbert Dynamics of a Dimer

    Master-uppsats, Uppsala universitet/Teoretisk fysik; Uppsala universitet/Materialteori

    Författare :Lee Johnson; [2022]
    Nyckelord :;

    Sammanfattning : The classical Landau-Lifshitz-Gilbert (LLG) equations are of crucialimportance in micro-magnetism, but a true quantum-mechanical descriptionwas not found until 2013. However, very few realistic quantumsystems have been modeled using it. LÄS MER

  7. 5. 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