Magnetic Traps and Guides for Bose-Einstein Condensates on an Atom Chip: Progress toward a Coherent Atom Waveguide Beamsplitter

<p>Atom interferometry has proven itself to be an extremely sensitive technology for measuring rotations, accelerations, and gravity. Thus far, atom interferometers have all been realized with atoms moving through free spacing and are restricted to the Mach- Zender configuration. However, if the atoms are guided, the shape of the interferometer can be customized to measure the inertial effect of interest, e.g. a ring or figure-eight interferometer could be realized. The enabling technology for guiding atoms is the \textquotedblrightatom chip,\textquotedblright where miniature copper wires are patterned onto a substrate and placed inside a vacuum chamber allowing the atoms to be only microns away. Current through these wires generates a magnetic field that can be configured to create a 2-D guiding potential or a 3-D trapping potential. My research has been focused on building a versatile apparatus for atom chip experiments with Bose-Einstein condensates (BEC) and studying the behavior of a BEC in a waveguide beam splitter, the primary element of an interferometer. Our apparatus collects <sup><span class="s1">87</span></sup>Rb atoms in a magneto-optical trap, precools them, and delivers them to the atom chip. On the chip we have demonstrated that we can capture the atoms in several types of micro-magnetic traps, and once the atoms are trapped, we evaporatively cool them to form a BEC. Our main focus has been using the BEC as a single mode atomic source for characterizing the coherence properties of a waveguide beamsplitter. To this point, small current deviations inside the 10 <span class="s2">\texttimes </span>20 <span class="s2">μ</span>m copper conductors prevent the coherent operation of the beamsplitter, and we propose ideas to improve the beamsplitter\textquoterights performance.</p>
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