ATOM OPTICS WITH MICROTRAPS AND ATOM CHIPS;: ASSEMBLING TOOLS FOR QUANTUM INFORMATION PROCESSING

Wire traps, based on the superposition of the magnetic fields of a current carrying wire and a homogeneous magnetic bias field oriented perpendicular to it, have proven to be able to capture large numbers of atoms, both thermal and Bose-Einstein condensed. Surface mounted wire traps and atom chips 112v3,4 enable extremely tight traps in various geometries while combining mechanical stability and robustness with low power consumption. They also allow the combination with optical elements, such as microresonators and cavities. These properties make the devices ideally suited for the realisation of various proposals on quantum information processing with neutral atoms '. A comprehensive review on trapping and manipulation of atoms with magnetic micro-traps can be found in '. The heart of the experiment is the atom chip. Since our microfabricated chip traps are usually too shallow and too small to capture a sufficient number of atoms to allow evaporative cooling to a large BEC, a robust copper structure is embedded in an ultra-high vacuum (UHV)-compatible ceramic directly behind the chip in the atom chip holder assembly (see Fig. 1). The copper structure can be operated with Uand Z-shaped currents (generat-