Sökning: "quantum"

Visar resultat 6 - 10 av 1574 avhandlingar innehållade ordet quantum.

  1. 6. Quantum photoelectrochemistry : Theoretical studies of organic adsorbates on metal oxides surfaces

    Författare :Petter Persson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum chemistry; Quantum chemistry; photoelectrochemistry; metal oxide surfaces; organic adsorbates; Kvantkemi; Quantum chemistry; Kvantkemi; Quantum Chemistry; kvantkemi;

    Sammanfattning : Interactions between organic molecules and transition metal oxide surfaces have been investigated by means of quantum chemical calculations. The studies have been aimed at understanding electrode-adsorbate interactions in photoelectrochemical devices, such as dye-sensitized solar cells. LÄS MER

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

    Författare :Erik Waltersson; Eva Lindroth; Stephanie Reimann; Stockholms universitet; []
    Nyckelord :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; Electronic structure; Elektronstruktur; fysik; Physics;

    Sammanfattning : 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. LÄS MER

  4. 8. Machine learning for quantum information and computing

    Författare :Shahnawaz Ahmed; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; quantum machine learning; quantum process tomography; quantum information; Machine learning; generative neural networks; variational quantum algorithms; quantum state tomography; optimization; quantum computing; Bayesian estimation;

    Sammanfattning : This compilation thesis explores the merger of machine learning, quantum information, and computing. Inspired by the successes of neural networks and gradient-based learning, the thesis explores how such ideas can be adapted to tackle complex problems that arise during the modeling and control of quantum systems, such as quantum tomography with noisy data or optimizing quantum operations, by incorporating physics-based constraints. LÄS MER

  5. 9. Quantum Holonomy for Many-Body Systems and Quantum Computation

    Författare :Vahid Azimi Mousolou; Erik Sjöqvist; Rosario Fazio; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Quantum holonomy; geometric phase; quantum correlations; quantum phase transitions; quantum computation; Natural Science; Naturvetenskap; Physics; Fysik;

    Sammanfattning : The research of this Ph. D. thesis is in the field of Quantum Computation and Quantum Information. A key problem in this field is the fragile nature of quantum states. LÄS MER

  7. 10. Quantum optics in constrained geometries

    Författare :Björn Hessmo; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Quantum chemistry; quantum optics; atom optics; complementarity; magnetic traps; laser cooling; quantum information; quantal phases; Kvantkemi; Quantum chemistry; Kvantkemi; Quantum Chemistry; kvantkemi;

    Sammanfattning : When light exhibits particle properties, and when matter exhibits wave properties quantum mechanics is needed to describe physical phenomena. A two-photon source produces nonmaximally entangled photon pairs when the source is small enough to diffract light. It is shown that diffraction degrades the entanglement. LÄS MER