ISBN 9783868538205

978-3-86853-820-5, Reihe Physik

Michael Grupp
Scattering in inhomogeneous systems

251 Seiten, Dissertation Universität Ulm (2011), Hardcover, B5

Zusammenfassung / Abstract

In this thesis we discuss applications of scattering theory in the framework of ultra-cold atomic gases. We start with an elementary review of scattering theory.

Feshbach resonances allow to tune the correlations between atoms in an ultra-cold atomic gas. We use elementary scattering situations as building blocks for analytically solvable models describing systems featuring Feshbach resonances.

The separability of the center-off-mass and relative motion in a two-particle problem in free space is a simplification relying on the translational invariance of the problem. In an optical lattice this is not anymore true. In a first step we reduce the problem to two interacting particles in an external potential.

Optical lattices have become a playground for quantum optics as well as solid state physics. Today, it is possible to study many-body systems at the lowest attainable temperature in the presence of designable optical lattices. We investigate how the presence of an optical lattice influences the emergence of two-particle Feshbach resonances. Moreover, we discuss collective Feshbach resonances in a two-component Bose-Einstein condensate trapped in a finite lattice.

Finally, we use the introduced basic elements of scattering theory and BEC as a starting point to an analytic model of the emergence of semifluxons in long Josephson junctions. We demonstrate its implementation in the context of ultra-cold matter waves using optical junctions.