Search for dissertations about: "Electric polarization"

Showing result 6 - 10 of 67 swedish dissertations containing the words Electric polarization.

  2. 6. Ensemble and Individual III-V Semiconductor Nanopillars: Optical Properties and Applications

    Author : Reza Sanatinia; Anand Srinivasan; Andrea Fiore; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nanopillar; nanowires; nanophotonics; nanofabrication; III-V semiconductors; photovoltaics; second-harmonic generation; top-down approach; colloidal lithography; antireflection; modal dispersion; polarization; nanowaveguide; indium phosphide; gallium arsenide; gallium phosphide; Physics; Fysik;

    Abstract : Optical properties of semiconductor nanowires (NWs)/nanopillars (NPs), as individual or ensemble, have attracted significant research interest in recent years. Their potential applications range from solid-state lighting, photovoltaics, lasing and nonlinear optics to sensing and life sciences. READ MORE

  4. 7. Role of charge and spin fluctuations and their interplay in solids : A Green’s function approach

    Author : Tor Sjöstrand; Matematisk fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Green’s function; correlations; collective excitations; screened interaction; electric polarization; orbital and spin magnetization; magnon-phonon interaction; Fierz ambiguity; time-dependent exchange-correlation potential;

    Abstract : Due to the large number of electrons, solid state physics boils down to many-body approximations in which only selected types of collective excitations are taken into account, guided by the emergent properties of the material under study. In this thesis, the collective excitations of primary interest are electronic charge and spin fluctuations(plasmons and magnons) and nuclear charge fluctuations (phonons). READ MORE

  5. 8. Polarization portraits of lightharvesting antennas: from single molecule spectroscopy to imaging

    Author : Rafael Camacho Dejay; Kemisk fysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Energy transfer; Single molecule spectroscopy; Exciton; Fluorescence microscopy; Fluorescence polarization; Light-harvesting; Chromophore; Conjugated Polymer; Photosynthesis;

    Abstract : Multichromophoric systems are very important in photosynthesis and any device that uses solar energy for its operation. This is because multichromophoric light-harvesting antennas are responsible for the absorption of light and the efficient transfer of the absorbed energy toward distinct places where it is to be used or stored. READ MORE

  6. 9. Geometrical controls on spectral induced polarization in time and frequency domain

    Author : Sara Johansson; Teknisk geologi; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Spectral induced polarization; Microstructure; Electrical properties; Tomography; Multiscale;

    Abstract : What can we learn by transmitting electrical currents through electrodes in the ground? Geophysical methods can help us to locate the bedrock, valuable mineral ores, remains of ancient buildings and many other secrets hiding below the surface. However, it is not only the universal interest for the unknown that drives the geophysical research forward. READ MORE

  7. 10. Domain engineering in KTiOPO4

    Author : Carlota Canalias; Fredrik Laurell; Benoît Boulanger; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; quasi-phase matching; KTiOPO4; ferroelectric domains; atomic force microscopy; periodic electric field poling; polarization switching; second harmonic generation; Optical physics; Optisk fysik;

    Abstract : Ferroelectric crystals are commonly used in nonlinear optics for frequency conversion of laser radiation. The quasi-phase matching (QPM) approach uses a periodically modulated nonlinearity that can be achieved by periodically inverting domains in ferroelectric crystals and allows versatile and efficient frequency conversion in the whole transparency region of the material. READ MORE