Sökning: "topological charge"

Visar resultat 1 - 5 av 6 uppsatser innehållade orden topological charge.

  1. 1. Electron-skyrmion systems, in and out of equilibrium, and isolated or contacted to reservoirs

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

    Författare :Emil Adam Jonatan Östberg; [2023]
    Nyckelord :skyrmion; skyrmions; NEGF; freen s function; quantum transport; non-equlibrium; topology; topological charge; skyrmionics; current induced; open system; Physics and Astronomy;

    Sammanfattning : A Kondo lattice skyrmion model in contact with a macroscopic environment is simulated to explore skyrmion dynamics, which is an extension of previous work. The system is simulated using non-equilibrium Green's functions within the generalized Kadanoff-Baym ansatz and the wide band limit. LÄS MER

  3. 2. Characterization of Bi-incorporated InSb(111)A/B Surfaces : An STM and XPS Study

    Master-uppsats, Lunds universitet/Synkrotronljusfysik; Lunds universitet/Fysiska institutionen

    Författare :Shengpeng Huang; [2023]
    Nyckelord :indium antimonide; surface reconstructions; bismuth deposition; scanning tunneling microscopy; X-ray photoelectron spectroscopy.; Physics and Astronomy;

    Sammanfattning : In recent years, III-V semiconductor materials have received increasing attention due to their admirable electronic properties like direct tunable bandgaps and high charge carrier mobility. Indium Antimonide (InSb) possesses the largest electron mobility among III-V materials and is promising for infrared detectors, high-speed field effect transistors, and spintronics. LÄS MER

  4. 3. Characterization of InAs-Al semiconductor-superconductor hybrid devices

    Master-uppsats, Lunds universitet/Fasta tillståndets fysik; Lunds universitet/Fysiska institutionen

    Författare :Markus Aspegren; [2020]
    Nyckelord :quantum dot; superconductivity; quantum transport; josephson junction; spectroscopy; yu-shiba-rusinov; hybrid devices; sub-gap states; quantum computer; majorana bound state; bogoliubov quasiparticle; Physics and Astronomy;

    Sammanfattning : In this thesis we study charge and spin transport through InAs-Al nanowire superconductor-semiconductor hybrid devices. We focus on assessing the quality of the InAs-Al contact interface when using a weak HCl acid to wet-etch the nanowire surface prior to metal evaporation. LÄS MER

  5. 4. Topology-guided analysis and visualization of charge density fields

    Master-uppsats, Linköpings universitet/Institutionen för fysik, kemi och biologi; Linköpings universitet/Tekniska fakulteten

    Författare :Elvis Jakobsson; [2019]
    Nyckelord :Visualization; Topology; Charge density; Direct Volume Rendering; Crystal structure;

    Sammanfattning : Direct volume rendering techniques for scalar fields make use of transfer functions to map optical properties to the field; the field can subsequently be visualized through the drawing of isosurfaces in the volume spanned by the field. The utility of this approach is limited in the case of nested or clustered structures with the same isovalue and further does not easily allow for quantitative measurements of the visualized data. LÄS MER

  7. 5. Discussions on Dai-Freed Anomalies

    Master-uppsats, Uppsala universitet/Teoretisk fysik

    Författare :Huaiyu Li; [2019]
    Nyckelord :Anomaly; Quantum Fields Theory; Dai-Freed Theorem; Topology;

    Sammanfattning : In both field theories of high energy physics and field theories of condensed matter theories anomalies have been imposing constraints and bringing up new theories. While the perturbational and local anomalies from triangle diagrams are well-developed, we follow and review two works leading to non-perturbational global anomalies both related with Atiyah-Patogi-Sieger (APS) index theorem. LÄS MER