Sökning: "quantum wire"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden quantum wire.

  1. 1. Modelling of Quantum Transport in Nanostructures

    Författare :Dan Csontos; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ballistic transport; quantum wire; quantum dot; resonant tunnelling; three-terminal; disorder; Physics; Fysik; Fysicumarkivet A:2002:Csontos; scattering matrix; quantum transport;

    Sammanfattning : In this thesis, theoretical studies of the transport properties of three nanoscale systems: one-dimensional (1D) quantum wires (QWRs), zero-dimensional (0D), laterally confined, double-barrier resonant tunnelling structures (DBRTSs) and three-terminal ballistic junctions (TBJs), have been performed. In the first part of the thesis, an overview of the realization and properties of such systems is given along with a description of modelling tools used in the calculations. LÄS MER

  3. 2. Transport Studies of Local-Gate Defined Quantum Dots in Nanowires

    Författare :Carina Fasth; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Semiconductory physics; Fysik; Physics; quantum devices; nanowire; quantum dot; Halvledarfysik;

    Sammanfattning : This thesis focuses on electrical transport in semiconductor InAs nanowires grown by chemical beam epitaxy. Initially, transport length scales of homogeneous InAs n-type nanowires are characterized by low-temperature magnetoconductance measurements. The measurements show phase-coherent conductivity corrections. LÄS MER

  4. 3. 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

  5. 4. Quantum Devices from the Assembly of Zero- and One-Dimensional Building Blocks

    Författare :Claes Thelander; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; quantum devices; classical mechanics; quantum mechanics; relativity; statistical physics; thermodynamics; Matematisk och allmän teoretisk fysik; klassisk mekanik; kvantmekanik; relativitet; gravitation; termodynamik; statistisk fysik; Mathematical and general theoretical physics; single-electron transistor; nanowires; AFM; carbon nanotubes; Fysicumarkivet A:2003:Thelander;

    Sammanfattning : This thesis describes novel methods for the fabrication of nanometer-scale electronic devices, such as single-electron transistors and resonant tunneling diodes, from wire- and dot-shaped building blocks. The first part of the thesis describes the manipulation of metal nanoparticles and carbon nanotubes using an atomic force microscope. LÄS MER

  7. 5. Spin splitting in open quantum dots and related systems

    Författare :Martin Evaldsson; Igor Zozoulenko; Igor Abrikosov; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mesoscopic systems; 2DEG; ballistic transport; quantum dots; spin-polarised transport in quantum dots; spontanueous spin-splitting; Mesoscopic physics; Mesoskopisk fysik;

    Sammanfattning : This thesis addresses electron spin phenomena in semi-conductor quantum dots/anti-dots from a computational perspective. In the first paper (paper I) we have studied spin-dependent transport through open quantum dots, i.e., dots strongly coupled to their leads, within the Hubbard model. LÄS MER