Search for dissertations about: "quantum physics"

Showing result 1 - 5 of 677 swedish dissertations containing the words quantum physics.

  1. 1. On the role of the electron-electron interaction in two-dimensional quantum dots and rings

    University dissertation from Stockholm : Department of Physics, Stockholm University

    Author : Erik Waltersson; Stockholms universitet.; [2010]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; quantum dot; quantum ring; quantum dot molecule; electronic structure; two-dimensional; many-body physics; many-body perturbation theory; coupled cluster; coupled cluster singles and doubles; quantum logical gates; quantum computing; quantum control; quantum control algorithm; NATURAL SCIENCES Physics Condensed matter physics Electronic structure; NATURVETENSKAP Fysik Kondenserade materiens fysik Elektronstruktur; fysik; Physics;

    Abstract : Many-Body Perturbation Theory is put to test as a method for reliable calculations of the electron-electron interaction in two-dimensional quantum dots. We show that second order correlation gives qualitative agreement with experiments on a level which was not found within the Hartree-Fock description. READ MORE

  2. 2. Quantum Holonomy for Many-Body Systems and Quantum Computation

    University dissertation from Växjö : Linnaeus University Press

    Author : Vahid Azimi Mousolou; Linnéuniversitetet.; [2013]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Quantum holonomy; geometric phase; quantum correlations; quantum phase transitions; quantum computation; Natural Science; Naturvetenskap; Physics; Fysik;

    Abstract : The research of this Ph. D. thesis is in the field of Quantum Computation and QuantumInformation. A key problem in this field is the fragile nature of quantum states. READ MORE

  3. 3. Open Quantum Systems Effects in Interferometry, Quantum Computation, and Adiabatic Evolution

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Johan Åberg; Uppsala universitet.; [2005]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Physics; Open Systems; Completely Positive Maps; Channels; Decoherence; Quantum Information; Quantum Computing; Adiabatic Approximation; Quantum Search; Time-Complexity; Fysik; NATURAL SCIENCES Physics; NATURVETENSKAP Fysik;

    Abstract : The effects of open system evolution on single particle interferometry, quantum computation, and the adiabatic approximation are investigated.Single particle interferometry: Three concepts concerning completely positive maps (CPMs) and trace preserving CPMs (channels), named subspace preserving (SP) CPMs, subspace local channels, and gluing of CPMs, are introduced. READ MORE

  4. 4. Quantum Holonomies Concepts and Applications to Quantum Computing and Interferometry

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : David Kult; Uppsala universitet.; [2007]
    Keywords : Physics; Quantum Holonomy; Geometric Phase; Quantum Computation; Completely Positive Map; Mixed State; Interferometry; Fysik;

    Abstract : Quantum holonomies are investigated in different contexts.A geometric phase is proposed for decomposition dependent evolution, where each component of a given decomposition of a mixed state evolves independently. It is shown that this geometric phase only depends on the path traversed in the space of decompositions. READ MORE

  5. 5. Resonant Tunneling in Laterally Confined Quantum Structures

    University dissertation from Division of Solid State Physics, Department of Physics, Lund University,Box 118, SE-221 00 Lund, Sweden

    Author : Boel Gustafson; [2001]
    Keywords : 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;

    Abstract : 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. READ MORE