Sökning: "open quantum system"

Visar resultat 1 - 5 av 43 avhandlingar innehållade orden open quantum system.

  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 :NATURVETENSKAP; NATURAL SCIENCES; 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

  3. 2. 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. 3. Superconducting qubits - measurement, entanglement, and noise

    Författare :Lars Tornberg; Chalmers tekniska högskola; []
    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. 4. A General Formalism for Continuous Feedback Control in Quantum Systems

    Författare :Björn Annby-Andersson; NanoLund: Centre for Nanoscience; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; quantum measurements; quantum control; stochastic thermodynamics; information thermodynamics; full count- ing statistics; open quantum systems; Quantum measurements; Quantum control; Stochastic thermodynamics; Information thermodynamics; Full counting statistics; Open quantum systems;

    Sammanfattning : This thesis devolops a general formalism for continuous feedback control in quantum systems. The main result is a quantum Fokker-Planck master equation describing the joint dynamics of a quantum system and a detector with finite bandwidth. For a fast detector, this equation can be reduced to a Markovian master equation for the system dynamics. LÄS MER

  7. 5. Ensembles and Open Quantum Systems in Polaritonic Chemistry

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

    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