Search for dissertations about: "polarons"

Showing result 1 - 5 of 15 swedish dissertations containing the word polarons.

  2. 1. On the defective origin of conductive and structural properties of oxides: insights from first principles

    Author : Anders Lindman; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; point defects; thermodynamic modeling; proton conductors; oxyhydrides; density-functional theory; BaZrO3; polarons; grain boundaries; space charges; oxides;

    Abstract : Oxides are versatile materials with applications in many different research fields; especially those related to clean energy technologies, such as fuel cells, batteries and solar panels. Many functional properties of these materials derive from lattice imperfections, or defects, and a lot of effort has been put into fine tuning these materials by modifying their structure on the atomic scale. READ MORE

  4. 2. Triptych of quantum matter in one dimension : Playful constructions in theoretical and computational physics

    Author : Axel Gagge; Jonas Larson; Andrew Daley; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Bloch oscillations; Peierls; adiabatic; diabatic; ultracold atoms; Bose-Fermi mixtures; phonon; cQED; superradiance; polarons; DMRG; MPS; Kosterlitz-Thouless; Wannier; Bloch; quantum phase transitions; Theoretical Physics; teoretisk fysik;

    Abstract : In this compilation thesis, three different quantum mechanical systems are presented. All three have in common that they are one-dimensional quantum systems which, each in their own way, can be seen as analogous to other quantum systems. READ MORE

  5. 3. Theoretical studies of lattice- and spin-polarons

    Author : Nina Bondarenko; Olle Eriksson; Natalia Skorodumova; Manuel Pereiro; Maria Roser Valenti Vall; Uppsala universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Polaron; Nonlinear Schrödinger Equation; Nonlocality; Solitons; Integrable systems; Quantum field theory low energy ; Electron-phonon interaction; Density functional theory; Electronic structure of atoms and molecules; Spin-polaron; Langevin equation; Transport properties; Hubbard model; Heisenberg lattice; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Abstract : Theoretical studies of lattice- and spin-polarons are presented in this thesis, where the primary tool is ab-initio electronic structure calculations. The studies are performed with employment of a variety of analytical and computational methods. READ MORE

  6. 4. Image dipoles and polarons in organic semiconductors

    Author : Yongzhen Chen; Mats Fahlman; Xianjie Liu; Yiqiang Zhan; Linköpings universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Organic electronics; Interface dipole; Polaron; Conjugated polymer; Photoelectron spectroscopy; N-type doping; Electron transport material;

    Abstract : The rapid development of organic electronics depends on the synthesis of new π-conjugated molecules/polymers and the exploration of fundamental physics. However, most of the efforts have been concentrated on the former, leading to a lack of thorough understanding of many important concepts, which will become the ultimate limiting factor for overall performance and applications. READ MORE

  7. 5. Vibrational and Structural Characterisation in Two Perovskite Challenges: A Density Functional Theory Study

    Author : Erik Jedvik Granhed; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; phonon; chemical expansion; materials modelling; oxyhydride; polaron; vibrational analysis; BaTiO3; BaZrO3; anti-ferrodistortive; density functional theory;

    Abstract : The modelling of perovskites using density functional theory (DFT) can sometimes be a challenge with many different states very close in energy. In particular, the tilting of the inscribed octahedron, as well as the formation of electron polarons, leads to states with energy differences in the meV range. READ MORE