Sökning: "Holstein model"
Visar resultat 1 - 5 av 9 avhandlingar innehållade orden Holstein model.
1. Cultural Competence for Health Professionals : Instrument Development
Sammanfattning : In recent decades, both global migration in general and specifically migration to Sweden have increased. This development compels the need for delivering healthcare to the increasingly diverse populations in Sweden. LÄS MER
2. A Theoretical Study of Charge Transport in Molecular Crystals
Sammanfattning : The main objective of this thesis is to provide a deeper understanding of the charge transport phenomena occuring in molecular crystals. The focus is on the stability and the dynamics of the polaron as the charge carrier.To achieve this goal, a series of numerical calculations are performed using the semi-emprical "Holstien-Peierls" model. LÄS MER
3. Theoretical studies of lattice- and spin-polarons
Sammanfattning : 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. LÄS MER
4. Electron-Lattice Dynamics in pi-Conjugated Systems
Sammanfattning : 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. LÄS MER
5. Crossbreeding as a strategy in dairy cattle herds
Sammanfattning : This thesis aimed to explore benefits of dairy crossbreeding at herd level and form recommendations for dairy farmers, advisors, and breeding companies. A survey study revealed that Swedish dairy farmers can be divided into two groups: those supporting crossbreeding and those not supporting it. LÄS MER