Search for dissertations about: "Polaron dynamics"

Showing result 1 - 5 of 10 swedish dissertations containing the words Polaron dynamics.

2. 1. Electron-Lattice Dynamics in pi-Conjugated Systems

   Author : Magnus Hultell (Andersson); Sven Stafström; Alexander Onipko; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Polaron dynamics; Exciton dynamics; pi-conjugated systems; Su-Schrieffer-Heeger SSH model; Adiabaticity; Charge carrier transport; Organic electronics.; Computational physics; Beräkningsfysik;

   Abstract : In this thesis we explore in particular the dynamics of a special type of quasi-particle in pi-conjugated materials termed polaron, the origin of which is intimately related to the strong interactions between the electronic and the vibrational degrees of freedom within these systems. In order to conduct such studies with the particular focus of each appended paper, we simultaneously solve the time-dependent Schrödinger equation and the lattice equation of motion with a three-dimensional extension of the famous Su-Schrieffer-Heeger (SSH) model Hamiltonian. READ MORE

4. 2. Electron-lattice dynamics in π-conjugated systems

   Author : Magnus Hultell (Andersson); Sven Stafström; Alessandro Troisi; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; charge transport; electron-lattice dynamics; polaron; adiabatic transport; electron localization; internal conversion; Computational physics; Beräkningsfysik;

   Abstract : The work presented in this thesis concerns the dynamics in π-conjugated hydrocarbon systems. Due to the molecular bonding structure of these systems there exists a coupling between the electronic system and the phonons of the lattice. READ MORE

5. 3. Collective Excitation Dynamics in Molecular Aggregates

   Author : Mats Dahlbom; Kemisk fysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Chemistry; Kemi; Fysik; Physics; computational methods; photosynthesis; femtosecond spectroscopy; Exciton; Polaron;

   Abstract : The aim of this thesis is to study collective excitation dynamics in molecular aggregates. Half of the work presented here is method development and the remainder is application of these methods to several di.erent molecular aggregates. READ MORE

6. 4. Theoretical Description of the Electron-Lattice Interaction in Molecular and Magnetic Crystals

   Author : Elham Mozafari; Igor A. Abrikosov; Sven Stafström; George Malcolm Stocks; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Molecular crystals; Charge transport; Polaron; Magnetic materials; Paramagnetic state; Molecular dynamics;

   Abstract : Electron-lattice interactions are often considered not to play a major role in material's properties as they are assumed to be small, the second-order effects. However, this study shows the importance of taking these effects into account in the simulations. READ MORE

7. 5. 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