An atom Michelson interferometer is implemented on an "atom chip." The chip uses lithographically patterned conductors and external magnetic fields to produce and guide a Bose-Einstein condensate. Splitting, reflecting, and recombining of condensate atoms are achieved by a standing-wave light field having a wave vector aligned along the atom waveguide. A differential phase shift between the two arms of the interferometer is introduced by either a magnetic-field gradient or with an initial condensate velocity. Interference contrast is still observable at 20% with an atom propagation time of 10 ms.

-We demonstrate sub-Doppler cooling of 40 K on the D1 atomic transition. Using a gray molasses scheme, we efficiently cool a compressed cloud of 6.5 × 10 8 atoms from ∼ 4 mK to 20 µK in 8 ms. After transfer in a quadrupole magnetic trap, we measure a phase space density of ∼ 10 −5 . This technique offers a promising route for fast evaporation of fermionic 40 K.

We demonstrate area-enclosing atom interferometry based on a moving guide. Light pulses along the free propagation direction of a magnetic guide are applied to split and recombine the confined atomic matter-wave, while the atoms are translated back and forth along a second direction in 50 ms. The interferometer is estimated to resolve ten times the earth rotation rate per interferometry cycle. We demonstrate a "folded figure 8" interfering configuration for creating a compact, large-area atom gyroscope with multiple-turn interfering paths.

Abstract:In a recent experiment [1], it was observed that a sequence of two standing wave square pulses can split a BEC at rest into +/-2 k diffraction orders with almost 100% efficiency.By truncating the Raman-Nath equations to a 2-state model, we provide an intuitive picture that explains this double square pulse beamsplitter scheme. We further show it is possible to optimize a standingwave multi square pulse sequence to efficiently diffract an atom at rest to symmetric superposition of +/-2n k diffraction order with n>1. The approach is considered to be qualitatively different from the traditional light pulse schemes in the Bragg or the Raman-Nath region, and can be extended to more complex atomic optical elements that produce various tailored output momentum states from a cold atom source.2