Ein planarer de Broglie-Wellenleiter

Abstract

Atom optical analoga exist for many light-optical elements like<br />mirrors, lenses and beam splitters. Light - or generally<br />electromagnetic fields - and matter virtually exchange roles: Optical<br />elements correspond to electromagnetic fields and light fields to<br />matter waves. The goal of this thesis was to realize a de Broglie<br />waveguide: A standing wave was generated by reflecting a laser beam on<br />a gold coated prism surface. Near the resonance frequency of an atomic<br />transition in metastable argon the light field exercises a dipole<br />force, which can be described by a potential proportional to the<br />intensity distribution of the interferece patterns of the light<br />field. Atoms with small enough kinetic energy can be stored in the<br />potential minima.<br /><br />In longitudinal direction to the standing wave the center of mass<br />motion of these atoms is strongly confined. It is characterised by a<br />discreet quantum mechanical mode structure where the energy distance<br />of the indivdual motional states is big compared to their<br />uncertainty. Transversally the atoms can virtually move freely,<br />i.e. their mode spectrum is continual. Therefore one single potential<br />minimum can be considered a resonator for atomic de Broglie waves and<br />can be regarded as the atom optical analogon of a two-dimensial<br />waveguide in light optics.<br /><br />A de Broglie waveguide provides a possiblity of examining a nearly<br />two-dimensional gas of ultracold atoms in front of a surface. Moreover<br />a continuous laser-like source of atoms may be realized on this<br />basis.