Sökning: "two-dimensional electron systems"

Visar resultat 11 - 15 av 52 avhandlingar innehållade orden two-dimensional electron systems.

  1. 11. Electron Transport and Optical Properties in Mesoscopic Systems

    Författare :Anna Grincwajg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The main subject of this Thesis is optical properties of quantum point contact systems and their influence on the electron transport. A quantum point contact is a narrow constriction in a two-dimensional electron gas, where the width of the constriction can be controlled by means of a gate voltage. LÄS MER

  3. 12. Quantum transport and spin effects in lateral semiconductor nanostructures and graphene

    Författare :Martin Evaldsson; Igor Zozoulenko; Vidar Gudmundsson; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Electronic transport; Spin related phenomena; Quantum dots; Quantum wires; Two-dimensional electron gas; 2DEG; Graphene; Computational physics; Beräkningsfysik; Physics; Fysik;

    Sammanfattning : This thesis studies electron spin phenomena in lateral semi-conductor quantum dots/anti-dots and electron conductance in graphene nanoribbons by numerical modelling. In paper I we have investigated spin-dependent transport through open quantum dots, i.e., dots strongly coupled to their leads, within the Hubbard model. LÄS MER

  4. 13. Transport phenomena in quantum wells and wires in presence of disorder and interactions

    Författare :Valeria Vettchinkina; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; time-dependent density-functional theory; disorder; electron correlation; Lowdimensional semiconducting systems; transport phenomena; Fysicumarkivet F:2012:Vettchinkina;

    Sammanfattning : Present-day electronics employ circuits of smaller and smaller dimensions, and today the length scales are so small that the laws of physics which rule micro-cosmos, quantum mechanics, become directly important. This thesis reports on theoretical work on electron transport in different nanostructures. LÄS MER

  5. 14. Antiferromagnets and Luttinger Liquids: Two Strongly Correlated Systems

    Författare :Ann Mattsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Strongly correlated systems show a variety of intriguing properties and have been extensively studied over the years. In this thesis two strongly correlated systems are discussed: the two-dimensional antiferromagnet and the Luttinger liquid. The Luttinger liquid has attracted much interest as a paradigm of non-Fermi liquid behavior. LÄS MER

  7. 15. Gaps, Traps and Lattices - Correlations in Small Quantum Systems

    Författare :Magnus Borgh; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetiska och optiska ; egenskaper elektriska; Cold atoms; Quantum dots; Optical lattices; classical mechanics; Mathematical and general theoretical physics; Exact diagonalization; Density Functional Theory; Vortices; relativity; quantum mechanics; termodynamik; statistisk fysik; relativitet; kvantmekanik; klassisk mekanik; Matematisk och allmän teoretisk fysik; thermodynamics; statistical physics; Condensed matter:electronic structure; gravitation; supraledare; magnetisk resonans; electrical; magnetic and optical properties; supraconductors; magnetic resonance; relaxation; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; spektroskopi; Fysicumarkivet A:2007:Borgh;

    Sammanfattning : This dissertation investigates properties of two-dimensional many-body systems. Studies are performed using the Spin-Density Functional Theory with the Local Spin-Density Approximation, and numerical exact diagonalization. LÄS MER