Path integral Monte Carlo simulations and their relation to recent advances in nanophysics

The thesis consists of three parts. In part one an introduction to the path integral Monte Carlo method (PIMC) and an overview on the experimental techniques for making nanoscopic semiconductor structures are given. Part two consists of two already published articles on the application of PIMC to nanoscopic quantum dots and quantum rings. In the case of quantum dots, shell effects and electron correlations for up to 12 electrons are studied. Furthermore, the addition energies are qualitatively reproduced using PIMC. In nanoscopic quantum rings, a parameter dependent transition between a spin ordered and disordered Wigner crystal is found. Further chapters are on the application of PIMC to quantum dot molecules and sodium clusters. It is shown that quantum dot molecules can be utilized to implement logical functions. PIMC is able to study the geometry of small sodium clusters, where the interaction between cores and valence electrons is modelled by a pseudopotential. The cores are treated as classical particles. Part three is on thermodynamic properties of finite systems and consists of three already published articles. While the first chapter of this part is about a recursion formula for the canonical occupation number, in the following chapters a new classification scheme for phase transitions in finite systems utilizing the zeros of the canonical partition function is introduced and applied to different systems.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Universität Oldenburg

Year

2001

Author dc:creator

• Harting, Jens

• [Keine Schlagwörter von Autor/in vergeben.]

Repository record source_url

http://oops.uni-oldenburg.de/274

OAI identifier oai:identifier

oai:oops.uni-oldenburg.de:274