Improvements and Applications of a Guided-Wave Bose Einstein Condensate Interferometer.

摘要

This work was done with thesis advisor Charles Sackett. An atom interferometer using a coherent matter wave of 87 Rubidium in a Bose-Einstein condensate confined in a magnetic atom wave guide was analyzed for limitations and adapted to several measurement applications. The atom wave guide that confines the BEC wave packets and supports them against gravity provides flexibility for the apparatus and the possibility of miniaturization, but is shown to be a major limitation in its first implementation. Confinement limits stable interferometer measurement times and wave packet separations to 72 ms and 0.47 mm respectively or 96 ms and 0.29 mm depending configuration. Unstable measurements are demonstrated at 0.9 s. Confinement effects are discussed in detail including limitations and sources of error for future measurements.;A second implementation is constructed and shown to reduce the confinement limitations making 160 ms times and 0.94 mm separations possible in the 72 ms--0.47 mm configuration were it not for the now dominating limitation of atom interferometer signal noise sourced from mechanical vibrations.;The interferometer has been adapted to make several measurements. In addition to experiments to measure gravity and the dynamic polarizability of Rubidium discussed recently in previous theses from this research group, two new experiments are developed to measure rotation and the static polarizability of Rubidium in the ground state. The rotation experiment used an interferometer working in two dimensions to take advantage of the Sagnac effect. The area enclosed by the interferometer is proportional to sensitivity, and here 0.15 mm2 areas are demonstrated, making a device sensitive to rotations of the order of 100 murad/s. Again, signal noise is the major limitation.;The static polarizability experiment involved placing a one dimensional atom interferometer in a well calibrated static electric field. A precision measurement could not be made due to insufficient optical access. Instead knowledge of the polarizability was used to partially verify the electric field calibration demonstrating the viability of the technique for future measurements. Both experiments show promise of becoming precision measurements and future improvements are discussed.