Sökning: "matter theory"
Visar resultat 6 - 10 av 739 avhandlingar innehållade orden matter theory.
6. Transport theory and finite element methods for mesoscopic superconducting devices
Sammanfattning : At low temperatures, electrons in a superconductor exhibit pairing correlations that result in a macroscopic, phase-coherent ground state. This leads to peculiar electromagnetic properties such as the flow of dissipationless charge currents and expelling of external magnetic fields. LÄS MER
7. Spin ice and demagnetising theory
Sammanfattning : Frustration, or the inability to simultaneously minimise all local interactions is, a phenomenon occurring in a broad number of physical systems. We will in this thesis focus on a class of frustrated ferromagnetic materials called spin ices and how both numerical and experimental techniques can be used to understand their properties. LÄS MER
8. Cosmoparticle Physics and String Theory
Sammanfattning : This thesis deals with phenomenological and theoretical aspects of cosmoparticle physics and string theory. There are many open questions in these topics. In connection with cosmology we would like to understand the detailed properties of dark matter, dark energy, generation of primordial perturbations, etc. LÄS MER
9. Ultracold rubidium atoms in periodic potentials
Sammanfattning : This thesis includes both experimental and theoretical investigations, presented in a series of eight papers. The experimental part ranges from the construction procedures of an apparatus for Bose-Einstein condensates, to full scale experiments using three different set-ups for ultracold atoms in optical lattices. LÄS MER
10. One-dimensional theory of the quantum Hall system
Sammanfattning : The quantum Hall (QH) system---cold electrons in two dimensions in a perpendicular magnetic field---is a striking example of a system where unexpected phenomena emerge at low energies. The low-energy physics of this system is effectively one-dimensional due to the magnetic field. LÄS MER