Search for dissertations about: "Fysik och astronomi med inriktning mot teoretisk fysik"

Showing result 1 - 5 of 6 swedish dissertations containing the words Fysik och astronomi med inriktning mot teoretisk fysik.

  1. 1. The Electronic Structure of Organic Molecular Materials : Theoretical and Spectroscopic Investigations

    Author : Iulia Emilia Brumboiu; Barbara Brena; Biplab Sanyal; Olle Eriksson; Jakob Schiøtz; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; NATURAL SCIENCES; materials theory; electronic structure; photoelectron spectroscopy; near-edge X-ray absorption fine structure; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik; Materialvetenskap; Materials Science;

    Abstract : In the present thesis the electronic properties of two organic molecules were studied by means of density functional theory (DFT) in connection to their possible applications in organic photovoltaics and molecular spintronics respectively.The first analysed system is the C60 derivative PCBM extensively used in polymer solar cells for the charge separation process. READ MORE

  2. 2. Probing Magnetism at the Atomic Scale:  Non-Equilibrium Statistical Mechanics Theoretical Treatise

    Author : Juan David Vasquez Jaramillo; Jonas Fransson; Rosa Lopez; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Non-Equilibrium Statistical Mechanics; Magnetism; Quantum Optics; Quantum Coherence; RKKY; Colciencias; Equation of Motion; Jauho-Meir-Wingreen Formalism; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik; Physics with specialization in Quantum Chemistry; Fysik med inriktning mot kvantkemi; Physics and Astronomy specializing in Theoretical Physics; Fysik och astronomi med inriktning mot teoretisk fysik;

    Abstract : Here, I present a theoretical study, based on non-equilibrium quantum statistical mechanics and on the non-equilibrium extension to the RKKY intveraction,where I investigate the emergence of magnetism at the atomic scale in adsorbed molecular complexes hosting localized spin moments, at the stake of being probed with scanning tunneling microscopy tip, and being driven by a temperature gradient and gated by an electric field. The scanning tunneling microscopy set up is modeled as a molecular junction with a magnetic molecule embedded within it, where the molecule consists in a set of electronic levels resembling the typical s-p orbitals of a metal hydride or an organometal, and a localized spin moment resembling the magnetic unit hosted by the latter and former type of molecules mentioned. READ MORE

  3. 3. Scattering Amplitudes in Supersymmetric Quantum Chromodynamics and Gravity

    Author : Gregor Kälin; Henrik Johansson; Lance J. Dixon; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Scattering Amplitudes; Supersymmetric Gauge Theory; Supergravity; Quantum Chromodynamics; Physics and Astronomy specializing in Theoretical Physics; Fysik och astronomi med inriktning mot teoretisk fysik;

    Abstract : Quantum field theory is a theoretical framework for the description of nature in terms of fundamental particles, fields and their interactions. In the quantum regime, elementary scattering processes are observables in many experiments and studied in theoretical physics. READ MORE

  4. 4. Atomic Processes in Stellar Atmospheres : Inelastic Collisions and Effects on Late-type Spectra

    Author : Yeisson Fabian Martinez Osorio; Paul Barklem; Karin Lind; Nikolai Piskunov; Carlos Allende Prieto; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Spectral line: formation; atomic data; stellar abundances.; Fysik med inriktning mot astrofysik; Physics with specialization in Astrophysics;

    Abstract : Chemical abundances as measured from stellar spectral lines are often subject to uncertainties due to lack of accurate data for inelastic collisions, which is needed for non-local thermodynamic equilibrium (non-LTE) modelling. For cool stars, understanding of collision processes with electrons and hydrogen atoms is required to achieve high precision measurements. READ MORE

  5. 5. Bending, Twisting and Turning : Protein Modeling and Visualization from a Gauge-Invariance Viewpoint

    Author : Martin Lundgren; Antti Niemi; Jørgen Ellegaard Andersen; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; protein folding; discrete frenet frame; solitons; protein visualization; Physics and Astronomy specializing in Theoretical Physics; Fysik och astronomi med inriktning mot teoretisk fysik;

    Abstract : Proteins in nature fold to one dominant native structure. Despite being a heavily studied field, predicting the native structure from the amino acid sequence and modeling the folding process can still be considered unsolved problems. In this thesis I present a new approach to this problem with methods borrowed from theoretical physics. READ MORE