Search for dissertations about: "quantum well"

Showing result 16 - 20 of 576 swedish dissertations containing the words quantum well.

  2. 16. Resonant Tunneling in Laterally Confined Quantum Structures

    Author : Boel Gustafson; Fasta tillståndets fysik; []
    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

  4. 17. Quantum Coherence and Quantum-Vacuum Effects in Some Artificial Electromagnetic Media

    Author : Jianqi Shen; Sailing He; Chris Phillips; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Quantum coherence; quantum vacuum; electromagnetically induced transparency; negative refractive index; artificial electromagnetic media; electric- and magnetic-dipole transitions; multilevel atomic vapors; transient evolution; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Abstract : The author of this thesis concentrates his attention on quantum optical properties of some artificial electromagnetic media, such as quantum coherent atomic vapors (various multilevel electromagnetically induced transparency vapors) and negative refractive index materials, and suggests some possible ways to manipulate wave propagations inside the artificial electromagnetic materials based on quantum coherence and quantum vacuum effects. In Chapters 1 and 2, the author reviews the previous papers on quantum coherence as well as the relevant work such as electromagnetically induced transparency (EIT), atomic population trapping and their various applications. READ MORE

  5. 18. Surface-normal multiple quantum well electroabsorption modulators : for optical signal processing and asymmetric free-space communication

    Author : Stéphane Junique; Lars Thylén; Uzi Efron; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spatial light modulators; quantum wells; optical resonator; Fabry–Pérot cavity; electroabsorption modulator; free–space optical communication; Photonics; Fotonik;

    Abstract : Electroabsorption is the physical phenomenon by which the absorption of light in a medium can be controlled by applying an electric field. The Quantum–Confined Stark Effect, which makes the absorption band–edge in quantum wells very field–dependent, together with the strong absorption peak provided by excitons, are the physical foundations for the success of electroabsorption modulators based on quantum well structures in telecommunication networks. READ MORE

  6. 19. Quantum acoustics with superconducting circuits

    Author : Gustav Andersson; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; superconducting qubits; cluster states; SAW; two-level systems; circuit QED; giant atoms; two-mode squeezing; surface acoustic wave; quantum acoustics; hybrid quantum systems;

    Abstract : The past 20 years has seen rapid developments in circuit quantum electrodynamics, where superconducting qubits and resonators are used to control and study quantum light-matter interaction at a fundamental level. The development of this field is strongly influenced by quantum information science and the prospect of realizing quantum computation, but also opens up opportunities for combinations of different physical systems and research areas. READ MORE

  7. 20. Controllable coupling of superconducting qubits and implementation of quantum gate protocols

    Author : Margareta Wallquist; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Controllable Qubit-Coupling; Single Cooper-Pair Box; Josephson Effect; Quantum Gate; Superconducting Circuit; Quantum Computer; Qubit; Quantum Electrical Circuit;

    Abstract : The concept of a quantum computer was invented in the beginning of the 1980s as a quantum generalization of the reversible classical computer. After discoveries in the middle of the 1990s of quantum algorithms, which wouldsolve some problems considered intractable for classical computers, the field of quantum computing has developed rapidly. READ MORE