Sökning: "optical calculations with density functional theory"

Visar resultat 1 - 5 av 39 avhandlingar innehållade orden optical calculations with density functional theory.

1. 1. The interaction of hydrogen with metallic glass

   Författare :Johan Bylin; Gunnar K. Pálsson; Ralph H. Scheicher; Gabriella Andersson; Astrid Pundt; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; metallic glass; hydrogen; thin film; density functional theory; stochastic quenching; molecular dynamics; x-ray diffraction; pair distribution function; neutron reflectometry; volume expansion; elastic hydrogen-hydrogen interaction; dipole force tensor; electronic structure; optical conductivity; resistivity; optical transmission; x-ray photoelectron spectroscopy; thermodynamic driving force; Gibbs free energy; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : Combining theoretical ab initio calculations with high-purity thin film sample synthesis and in situ measurements is a compelling way to bridge the gap in our understanding concerning hydrogen in metallic glasses, which is the primary work of this dissertation thesis. The main emphasis has been on how hydrogen affects the structure of metallic glasses, and how those changes influence not only the electronic properties of the amorphous metals but also their thermal stability. LÄS MER

3. 2. Designing and Tuning the Properties of Materials by Quantum Mechanical Calculations

   Författare :Jailton Souza de Almeida; Rajeev Ahuja; Patrizia Monachesi; Uppsala universitet; []
   Nyckelord :Physics; Density Functional Theory; Electronic Structure; Phase Transitions; High Pressure; Optical Properties; Dielectric Functions; Semiconductors; Metals; Fysik;

   Sammanfattning : In many materials, changes in chemical composition, pressure or temperature can induce metal to insulator transitions. It is recently observed in yttrium hydride, for example, changes from a shiny mirror (YH2) to a transparent window (YH3), which has important technological application in optical devices. LÄS MER

4. 3. Gaps, Traps and Lattices - Correlations in Small Quantum Systems

   Författare :Magnus Borgh; Matematisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetiska och optiska ; egenskaper elektriska; Cold atoms; Quantum dots; Optical lattices; classical mechanics; Mathematical and general theoretical physics; Exact diagonalization; Density Functional Theory; Vortices; relativity; quantum mechanics; termodynamik; statistisk fysik; relativitet; kvantmekanik; klassisk mekanik; Matematisk och allmän teoretisk fysik; thermodynamics; statistical physics; Condensed matter:electronic structure; gravitation; supraledare; magnetisk resonans; electrical; magnetic and optical properties; supraconductors; magnetic resonance; relaxation; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; spektroskopi; Fysicumarkivet A:2007:Borgh;

   Sammanfattning : This dissertation investigates properties of two-dimensional many-body systems. Studies are performed using the Spin-Density Functional Theory with the Local Spin-Density Approximation, and numerical exact diagonalization. LÄS MER

5. 4. Calculations of Clean and Adsorbate Covered Metal Surfaces and their Core-Level Photoemission Spectra

   Författare :Martin Birgersson; Matematisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; chemical shifts; density functional theory; Condensed matter:electronic structure; electrical; magnetic and optical properties; supraconductors; magnetic resonance; relaxation; Atomic and molecular physics; spektroskopi; magnetisk resonans; supraledare; magnetiska och optiska ; egenskaper elektriska; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; core-level photoemission; single crystal surfaces; Atom- och molekylärfysik; Fysicumarkivet A:2002:Birgersson; core-hole degeneracies; metal surfaces; adsorption; molecular vibrations;

   Sammanfattning : The present thesis is concerned with the theoretical study of x-ray photoemission spectra from clean and adsorbate-covered metal surfaces. The main tool is ab initio density functional (DFT) total energy calculations. LÄS MER

7. 5. Geometrical Structure, Phase Diagrams, and Core-Level Binding Energiesof Metal Surfaces: Calculations, Simulations, and Experiments

   Författare :Mikael Borg; Synkrotronljusfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; adsorption; chemical shifts; low energy electron diffraction; Monte Carlo simulations; Condensed matter:electronic structure; electrical; magnetic and optical properties; Kondenserade materiens egenskaper:elektronstruktur; spectroscopy; relaxation; magnetic resonance; supraconductors; spektroskopi; magnetisk resonans; supraledare; egenskaper elektriska; magnetiska och optiska ; molecular vibrations; density functional theory; single crystal surfaces; core-level photoemission; metal surfaces; Fysicumarkivet A:2003:Borg;

   Sammanfattning : This thesis concerns clean and adsorbate covered metal surfaces and surface alloys. These systems have been studied using theoretical and experimental methods. In the first part of the thesis, the different techniques that have been utilized in this work are presented, and the included publications are summarized. LÄS MER