Search for dissertations about: "tunneling Hamiltonian"

Showing result 1 - 5 of 8 swedish dissertations containing the words tunneling Hamiltonian.

  2. 1. On the Properties of Some Strongly Correlated Systems - Analytical and Numerical Studies

    Author : Jurij Smakov; KTH; []
    Keywords : mean field theory; magnetic multilayers; Curie temperature; compensation temperature; scanning tunneling microscopy; tunneling; superconductivity; local density of states; Josephson effect; tunneling Hamiltonian formalism; impurities in superconducto;

    Abstract : This thesis is dedicated to analytical and numerical studiesof a few models of strongly correlated systems and thedevelopment of techniques for such studies. The common name"strongly correlated" refers to systems in which theinteractions (correlations) between the constituent particleslead to nontrivial properties, such as various types ofmagnetism, superconductivity, and exotic phases. READ MORE

  4. 2. Theoretical modeling of scanning tunneling microscopy

    Author : Alexander Gustafsson; Magnus Paulsson; Jorge Iribas Cerdá; Linnéuniversitetet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Scanning tunneling microscopy; Computational models; Quantum tunneling; Green s functions; Density functional theory; Condensed Matter Physics; Kondenserade materians fysik;

    Abstract : The main body of this thesis describes how to calculate scanning tunneling microscopy (STM) images from first-principles methods. The theory is based on localized orbital density functional theory (DFT), whose limitations for large-vacuum STM models are resolved by propagating localized-basis wave functions close to the surface into the vacuum region in real space. READ MORE

  5. 3. Collective Electron Dynamics in Mesoscopic Systems

    Author : Oleksandr Zazunov; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Andreev reflection; Josephson effect; qubit; composite fermions; Andreev levels; resonant tunneling; superconductivity; high-T c superconductors; quantum point contact; fractional quantum Hall effect;

    Abstract : This work is devoted to a theoretical investigation of collective electron dynamics in low dimensional materials and mesoscopic structures. A common feature of these studies is the focus on the properties of the low energy dynamics of conduction electrons. One class of studied materials is the high-Tc superconductor Nd2CuO4 and related compounds. READ MORE

  6. 4. Effects of Spin-Orbit Interactions in Ferromagnetic Metal Nanoparticles

    Author : Aleksander Cehovin; Matematisk fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; electrical; magnetic and optical properties; elementary spin excitations; spektroskopi; magnetisk resonans; supraledare; electron tunneling spectroscopy; Condensed matter:electronic structure; magnetic anisotropy; spin-orbit interactions; magnetism in nanostructures; egenskaper elektriska; ferromagnetic materials; magnetiska och optiska ; Kondenserade materiens egenskaper:elektronstruktur; relaxation; spectroscopy; supraconductors; magnetic resonance; Fysicumarkivet A:2003:Cehovin;

    Abstract : This thesis is a theoretical investigation of the effects of spin-orbit (SO) interactions in ferromagnetic metal nano-particles. Part I of the thesis is devoted to an elementary introduction of the research field, including recent experimental advances which partly motivated the work presented here. READ MORE

  7. 5. Non-Orthogonality and Electron Correlations in Nanotransport : Spin- and Time-Dependent Currents

    Author : Jonas Fransson; Antti-Pekka Jauho; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; non-orthogonality; non-equilibrium; transport; nanosystem; quantum dot; spin-dependent; renormalization; Green function; diagram technique; many-body states; Hubbard operator; electron correlations; time-dependent; Fysik; icke-ortogonal; icke-jämvikt; transport; nanosystem; kvantprick; spinberoende; renormering; Green-funktion; diagramteknik; mångkropparstillstånd; Hubbadoperator; elektronkorrelationer; tidsberoende; Physics; Fysik; Fysik; Physics;

    Abstract : The concept of the transfer Hamiltonian formalism has been reconsidered and generalized to include the non-orthogonality between the electron states in an interacting region, e.g. quantum dot (QD), and the states in the conduction bands in the attached contacts. READ MORE