A Michelson interferometer using Bose-Einstein condensates is demonstrated with coherence times of up to 44 ms and arm separations up to 180 m. This arm separation is larger than that observed for any previous atom interferometer. The device uses atoms weakly confined in a magnetic guide and the atomic motion is controlled using Bragg interactions with an off-resonant standing-wave laser beam.

We describe a novel atom trap for Bose-Einstein condensates of 87 Rb to be used in atom interferometry experiments. The trap is based on a time-orbiting potential waveguide. It supports the atoms against gravity while providing weak confinement to minimize interaction effects. We observe harmonic oscillation frequencies (ω x ,ω y ,ω z ) as low as 2π × (6.0, 1.2, 3.3) Hz. Up to 2 × 10 4 condensate atoms have been loaded into the trap, at estimated temperatures as low as 850 pK.We anticipate that interferometer measurement times of 1 s or more should be achievable in this device.