Sökning: "NEGF"

Hittade 4 uppsatser innehållade ordet NEGF.

  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. Simulating the Effect of Spatial Potential Variation in Nanodevices with the NEGF Method

    Master-uppsats, Lunds universitet/Institutionen för elektro- och informationsteknik

    Författare :Markus Berthilsson; [2022]
    Nyckelord :Technology and Engineering;

    Sammanfattning : In this master thesis nanowires have been simulated to study the effect of spatial imperfections in the nanowires. This spatial imper- fection took the form of potential fluctuations in the conduction band across the wire. LÄS MER

  4. 3. Green's Functions Investigations in Quantum Transport Geometries

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

    Författare :Philip Johansson; [2022]
    Nyckelord :Quantum transport; Green s functions; self-energy; non-equilibrium; many-body physics; Physics and Astronomy;

    Sammanfattning : In this thesis we employ the non-equilibrium Green’s function (NEGF) method to study both finite and infinite systems. We develop a codebase capable of computing the steady state interacting NEGF in open systems, i.e. LÄS MER

  5. 4. Electric Field Domains in Quantum Cascade Lasers

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

    Författare :Tim Almqvist; [2017]
    Nyckelord :quantum cascade laser; QCL; electric field domain; EFD; NDR; negative differential resistivity; simulations; Tim; Almqvist; kvantkaskadlaser; Physics and Astronomy;

    Sammanfattning : Quantum cascade lasers (QCLs) are periodic semiconductor heterostructures, capable of producing laser gain. They have become an important source of coherent radiation in the mid infrared, and THz frequency regions. QCLs are non-linear electric devices, and often have bias regions of negative differential resistivity (NDR). LÄS MER