Sökning: "Low temperature physics"

Visar resultat 11 - 15 av 450 avhandlingar innehållade orden Low temperature physics.

1. 11. Resonant Tunneling in Laterally Confined Quantum Structures

   Författare :Boel Gustafson; Fasta tillståndets fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; gravitation; relativity; quantum mechanics; classical mechanics; Mathematical and general theoretical physics; Fysik; Physics; High peak-to-valley ratio; Lateral confinement; Quantum dots; Resonant tunneling; Self-assembled quantum dots; Schottky depletion; Buried metal gate; Electron transport; Magnetic-field dependence; Energy level width; Tunneling transistors; Mode coupling; statistical physics; thermodynamics; Matematisk och allmän teoretisk fysik; klassisk mekanik; kvantmekanik; relativitet; statistisk fysik; termodynamik; Technological sciences; Teknik; Fysicumarkivet A:2001:Gustafson;

   Sammanfattning : In the thesis, three-dimensionally confined resonant tunneling structures were studied experimentally. Two approaches were used for obtaining quantum confinement: gate-defined lateral constriction of double barrier structures, and epitaxial growth of self-assembled quantum dots. LÄS MER

3. 12. Hybrid superconductor junctions with diluted PtNi ferromagnetic interlayer

   Författare :Taras Golod; Vladimir M. Krasnov; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Superconductivity; Supraledning; Low temperature physics; Lågtemperaturfysik; materiefysik; Physics Of Matter; Solid State Physics; fasta tillståndets fysik;

   Sammanfattning : This thesis describes experimental investigation of thin films made of diluted Pt 1-x Ni x ferromagnet alloy and Nb-Pt 1-x -Nb Josephson junctions. Such Hybrid Superconductor-Ferromagnet (S-F) Structures are of significant interest because of the new physics involved and possible applications in low temperature and spintronic devices. LÄS MER

4. 13. Quantum electronic transport in low-dimensional semiconductors

   Författare :Heiner Linke; Fasta tillståndets fysik; []
   Nyckelord :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

5. 14. 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

7. 15. Low and High Energy Ion Beams in Nanotechnology

   Författare :Thomas Winzell; Kärnfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ion implantation; magnetic materials; ERDA; nanometer structures; Nuclear physics; MeV Ions; lithography; Kärnfysik; Fysicumarkivet A:2000:Winzell;

   Sammanfattning : In this thesis, two ways of fabrication of nanometer-sized semiconductor features are presented. Low Energy Ion Implantation (LEII) has been used to create shallow (sub-50 nm) and laterally small (5 m m – 200 nm) features by 10 keV As+ doping of B background doped Si. LÄS MER