Implementation of a Bose Einstein condensate gyroscope

Atom interferometers using Bose Einstein condensates have been demonstrated in linear geometries and have given promising results. These interferometers often use magnetic fields to confine the atoms and to support them against gravity. Here we demonstrate a two-dimensional interferometer in harmonic magnetic trap. Such an interferometer can take advantage of the Sagnac effect for rotation and make gyroscopic measurements. Compared to free space interferometers, much larger interactions times and enclosed areas can in principle be achieved, since the atoms are not falling. In our implementation, we induce the atoms to oscillate along one direction by displacing the trap center. We then split and recombine the atoms along an orthogonal direction, using an off-resonant optical standing wave. The combination of the two motions produces an enclosed area. We observe interferometric contrast for areas up to 0.05 square mm, a value limited by the oscillation amplitude that we can reliably impart and by the coherence time of our linear interferometer.