Abstract
This dissertation, based on six included papers, theoretically investigates properties of quantum fewparticle systems. An overview of related experimental research  ultracold trapped dilute gases, and electrons in quantum dots  is given, followed by a description of some of the studied manyparticle phenomena  BoseEinstein condensation, quantized vortices, Wigner localization and the TonksGirardeau gas.
As the research results are presented in the included papers, a main part of the text in this thesis sets focus on methodology. Most of the papers involve use of the configuration interaction method, a numerical method which can give approximative eigenvalues and eigenstates of a fewparticle Hamiltonian. The research has also involved further development of this method, by use of the LeeSuzuki approximation. Formal descriptions of the methods are presented, together with a discussion about the numerical implementation. Explicit examples are given in an appendix.
Papers I and II investigate properties of a rotating twocomponent BoseEinstein condensate, in particular emerging vortex structures and associated wavefunctions.
Paper III demonstrates that the LeeSuzuki approximation, initially developed in the field of nuclear structure theory, can be useful to describe shortrange particleparticle correlations in a trapped bosonic gas.
Paper IV investigates the possibility to observe Wigner localization in a nanowire quantum dot, and compares predicted electron transport properties with experimental measurements.
Paper V analyzes structures of ultracold atoms or molecules with dipolar interactions, in a quasionedimensional trap.
Paper VI also considers cold atoms or molecules with dipolar interactions, but in a quasitwodimensional setup, with a focus on the resulting Wigner states' dependence on the anisotropy of the interaction.
As the research results are presented in the included papers, a main part of the text in this thesis sets focus on methodology. Most of the papers involve use of the configuration interaction method, a numerical method which can give approximative eigenvalues and eigenstates of a fewparticle Hamiltonian. The research has also involved further development of this method, by use of the LeeSuzuki approximation. Formal descriptions of the methods are presented, together with a discussion about the numerical implementation. Explicit examples are given in an appendix.
Papers I and II investigate properties of a rotating twocomponent BoseEinstein condensate, in particular emerging vortex structures and associated wavefunctions.
Paper III demonstrates that the LeeSuzuki approximation, initially developed in the field of nuclear structure theory, can be useful to describe shortrange particleparticle correlations in a trapped bosonic gas.
Paper IV investigates the possibility to observe Wigner localization in a nanowire quantum dot, and compares predicted electron transport properties with experimental measurements.
Paper V analyzes structures of ultracold atoms or molecules with dipolar interactions, in a quasionedimensional trap.
Paper VI also considers cold atoms or molecules with dipolar interactions, but in a quasitwodimensional setup, with a focus on the resulting Wigner states' dependence on the anisotropy of the interaction.
Original language  English 

Qualification  Doctor 
Awarding Institution 

Supervisors/Advisors 

Award date  2010 Dec 17 
ISBN (Print)  9789174730432 
Publication status  Published  2010 
Bibliographical note
Defence detailsDate: 20101217
Time: 13:15
Place: Lecture hall B, Department of Physics, Sölvegatan 14 A, Lund University Faculty of Engineering
External reviewer(s)
Name: Jain, Jainendra
Title: Professor
Affiliation: Pennsylvania State University, Pennsylvania, USA

The information about affiliations in this record was updated in December 2015.
The record was previously connected to the following departments: Mathematical Physics (Faculty of Technology) (011040002)
Subject classification (UKÄ)
 Physical Sciences
Free keywords
 TonksGirardeau gas
 vortices
 BoseEinstein condensation
 quantum manyparticle physics
 quantum fewparticle physics
 LeeSuzuki approximation
 configuration interaction method
 Wigner localization
 quantum dots
 ultracold gases
 Fysicumarkivet A:2010:Cremon