Sökning: "superfluidity"
Visar resultat 1 - 5 av 7 avhandlingar innehållade ordet superfluidity.
1. Ultracold atoms in optical potentials : from noise-induced transport to superfluidity
Sammanfattning : In this thesis, both experimental studies and numerical simulations of ultracold atoms in optical potentials are presented in a collection of nine scientific papers. In particular, noise-induced transport in dissipative optical lattices and superfluid properties of Bose-Einstein condensates have been studied. LÄS MER
2. Superfluidity and Supersolidity in Ultracold Atomic Gases Beyond Mean Field
Sammanfattning : This thesis investigates ultracold bosonic systems using an extended mean-field formalism with a focus on their superfluid and supersolid properties. The dissertation comprises five chapters and four articles, where the chapters provide some background to the research put forward in articles. LÄS MER
3. Vortices and Persistent Currents in Rotating Bose Gases - a Diagonalization Approach
Sammanfattning : In this thesis, I explore the behavior of rotating ultra-cold Bose gases, by diagonalizing the Hamiltonian. This method has the advantage of being exact in the limit of weak interactions, and thus is a useful complement to the more commonly used Gross-Pitaevskii (GP) equation, which relies on a mean-field approximation. LÄS MER
4. Bose-Einstein Condensation of Magnetic Excitons in Semiconductor Quantum Wells
Sammanfattning : In this thesis regimes of quantum degeneracy of electrons and holes in semiconductor quantum wells in a strong magnetic field are studied theoretically. The coherent pairing of electrons and holes results in the formation of Bose-Einstein condensate of magnetic excitons in a single-particle state with wave vector K. LÄS MER
5. Phase transitions in novel superfluids and systems with correlated disorder
Sammanfattning : Condensed matter systems undergoing phase transitions rarely allow exact solutions. The presence of disorder renders the situation even worse but collective Monte Carlo methods and parallel algorithms allow numerical descriptions. LÄS MER