Ultracold atoms on atom chips: Manipulation at the um distance scale

Miniaturized potentials near the surface of atom chips can be used as flexible and versatile tools for the manipulation of ultracold atoms on a microscale. The full scope of possibilities is only accessible if atom-surface distances can be reduced to microns. We discuss experiments in this regime and potential obstacles and solutions. We show that appropriate fabrication techniques lead to a reduction of disorder potentials so that one-dimensional condensates can be prepared. We demonstrate how electrostatic potentials can be used to modify magnetic trapping potentials and how they can be used to study condensate formation in situations of different dimensionality.