Sökning: "Open Quantum Systems"

Visar resultat 1 - 5 av 38 avhandlingar innehållade orden Open Quantum Systems.

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

    Författare :Johan Åberg; Erik Sjöqvist; Sten Lunell; Vlatko Vedral; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Physics; Open Systems; Completely Positive Maps; Channels; Decoherence; Quantum Information; Quantum Computing; Adiabatic Approximation; Quantum Search; Time-Complexity; Fysik; Physics; Fysik;

    Sammanfattning : 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. LÄS MER

  2. 2. Ensembles and Open Quantum Systems in Polaritonic Chemistry

    Författare :Eric Davidsson; Markus Kowalewski; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Polaritonic Chemistry; Optical Cavities; Open Quantum Systems; Quantum Simulations; Theoretical Physics; teoretisk fysik;

    Sammanfattning : Optical cavities—where spatial confinement can focus electromagnetic excitations—are able to couple matter to light with enough strength that the behaviour of the combined system is best understood in terms of polaritonic states; mixtures of excitations in both light and matter. This polaritonic regime provides a novel approach for modification and control of chemical reactions, and lately, experimental advancements are realising this potential. LÄS MER

  3. 3. Quantum Resources for Efficient Excitation Energy Transfer in Natural and Artificial Pigment-Protein Molecular Aggregates

    Författare :Charlotta Bengtson; Erik Sjöqvist; Susana Huelga; Uppsala universitet; []
    Nyckelord :Quantum coherence; quantum correlations; quantum nonlocality; open quantum systems; non-Markovian dynamics; Kemi med inriktning mot kvantkemi; Chemistry with specialization in Quantum Chemistry;

    Sammanfattning : Recently, long-lasting quantum effects in a number of photosynthetic complexes, which are pigment-protein molecular aggregates (PPMAs), were experimentally verified. These findings created an interest in trying to connect the known highly efficient excitation energy transfer (EET) in these systems to the existence of quantum effects such as quantum coherence and quantum correlations. LÄS MER

  4. 4. Superconducting qubits - measurement, entanglement, and noise

    Författare :Lars Tornberg; Chalmers University of Technology; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum Electric Circuits; Open Quantum Systems; Quantum Optics; Quantum Computing; Superconducting Qubits; Quantum Measurement;

    Sammanfattning : In the early 1980’s, it was suggested that a computer obeying the laws of quantum mechanics would be able to solve problems beyond the capabilities of a classical computer. The novel ways in which such a quantum computer works relies on the quantum properties of the quantum bits (qubits) used to store the information. LÄS MER

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

    Författare :Martin Evaldsson; Igor Zozoulenko; Igor Abrikosov; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; 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