Sökning: "two dimensional electron gas"

Visar resultat 1 - 5 av 48 avhandlingar innehållade orden two dimensional electron gas.

  1. 1. Quantum electronic transport in low-dimensional semiconductors

    Författare :Heiner Linke; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; quantum transport; two-dimensional electron gas; contact-free characterisation; ballistic transport; mesoscopic; electron billiard; quantum dot; electron-electron interaction; non-linear; phase breaking; Halvledarfysik; Fysicumarkivet A:1997:Linke; non-symmetric conductio; Semiconductory physics; low-dimensional structures;

    Sammanfattning : Electronic transport is studied at low temperatures in two-dimensional electron gases (2DEGs) and in mesoscopic semiconductor microstructures. The method of microwave-detection of the Shubnikov-de Haas effect for the contact-free characterisation of transport properties of 2DEGs is explored using both magnetic-field modulation and light-induced carrier modulation. LÄS MER

  2. 2. Electron Transport in Low Dimensional Systems

    Författare :Peter Ramvall; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; high mobility; low-dimensional structures; III-V semiconductors; quantum wells; heterojunctions; quantum Hall effect; edge channels; Shubnikov-de Haas effect; alloy-disorder scattering; Y-branch switch; two dimensional electron gas; Fysik; Fysicumarkivet A:1996:Ramvall; Physics; spin splitting; mag;

    Sammanfattning : This thesis consists of experimental studies of transport properties in high mobility two dimensional electron gases (2DEGs). Two material systems are used, an AlGaAs/GaAs heterojunction and a GaInAs/InP quantum well. LÄS MER

  3. 3. Nanoelectronic Devices Based on Low-Dimensional Semiconductor Structures

    Författare :Daniel Wallin; Fasta tillståndets fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; InGaAs InP; GaAs AlGaAs; ballistic transport; quantum transport; low-dimensional structures; two-dimensional electron gas; quantum dot; three terminal ballistic junction; nanowire;

    Sammanfattning : The present thesis reports on results from the fabrication technology development and the corresponding electrical transport measurements of low-dimensional semiconductor structures. The focus of the work has been directed towards two parts: the ballistic transport in nanostructure devices at room temperature, and the development of a charge-sensing technique for quantum dots (QD) in nanowires. LÄS MER

  4. 4. Electron energization in near-Earth space : Studies of kinetic scales using multi-spacecraft data

    Författare :Elin Eriksson; Andris Vaivads; Masahiro Hoshino; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; magnetic reconnection; electron acceleration; electron heating; magnetosheath; magnetotail; magnetic nulls; Cluster; Magnetospheric MultiScale; Fysik med inriktning mot rymd- och plasmafysik; Physics with specialization in Space and Plasma Physics;

    Sammanfattning : Plasma, a gas of charged particles exhibiting collective behavior, is everywhere in the Universe. The heating of plasma to millions of degrees and acceleration of charged particles to very high energies has been observed in many astrophysical environments. How and where the heating and acceleration occur is in many cases unclear. LÄS MER

  5. 5. Trace analysis of dioxins and dioxin-like PCBs using comprehensive two-dimensional gas chromatography with electron capture detection

    Författare :Conny Danielsson; Peter Haglund; Karin Wiberg; Jean-Marie Dimandja; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Comprehensive two-dimensional gas chromatography; GC × GC; µECD; PCDDs; PCDFs; dioxins; dioxin-like PCBs; Pressurized liquid extraction; PLE; PLE-C; food; feed; fly ash; soil; Environmental chemistry; Miljökemi;

    Sammanfattning : Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs), two groups of struc-turally related chlorinated aromatic hydrocarbons, generally referred to as “dioxins” are of great concern due to their extreme toxicity and presence in all compartments of the environment. Since they occur at very low levels, their analysis is complex and challenging, and there is a need for cost-efficient, reliable and rapid analytical alternatives to the expensive methods in-volving use of gas chromatography high-resolution mass spectrometry (GC-HRMS). LÄS MER