Sökning: "DNLS"
Hittade 4 avhandlingar innehållade ordet DNLS.
1. Comparisons between classical and quantum mechanical nonlinear lattice models
Sammanfattning : In the mid-1920s, the great Albert Einstein proposed that at extremely low temperatures, a gas of bosonic particles will enter a new phase where a large fraction of them occupy the same quantum state. This state would bring many of the peculiar features of quantum mechanics, previously reserved for small samples consisting only of a few atoms or molecules, up to a macroscopic scale. LÄS MER
2. Theoretical studies of Bose-Hubbard and discrete nonlinear Schrödinger models : Localization, vortices, and quantum-classical correspondence
Sammanfattning : This thesis is mainly concerned with theoretical studies of two types of models: quantum mechanical Bose-Hubbard models and (semi-)classical discrete nonlinear Schrödinger (DNLS) models.Bose-Hubbard models have in the last few decades been widely used to describe Bose-Einstein condensates placed in periodic optical potentials, a hot research topic with promising future applications within quantum computations and quantum simulations. LÄS MER
3. Discrete aperiodically ordered structures in low dimensions
Sammanfattning : This thesis deals with discrete models for one-dimensional (1D) and two-dimensional (2D) aperiodic systems such as quasicrystals and aperiodic superlattices. Various model systems are investigated using different forms of the tight-binding (TB) approximation. LÄS MER
4. A periodically Ordered Structures in One Dimension
Sammanfattning : This thesis deals with different aspects of aperiodically ordered structures in one dimension. The approach is entirely theoretical, and the models used have various relevance for real systems. LÄS MER
