C. A. Sackett

Bose-Einstein-condensate interferometer with macroscopic arm separation

A Michelson interferometer using Bose-Einstein condensates is demonstrated with coherence times of up to

Vacuum Pressure Measurements using a Magneto-Optical Trap

44\phantom{\rule{0.3em}{0ex}}\mathrm{ms}

Temperature stability of a dichroic atomic vapor laser lock

and arm separations up to

Measurement of the ac Stark shift with a guided matter-wave interferometer

180\phantom{\rule{0.3em}{0ex}}\mathrm{\ensuremath{\mu}}\mathrm{m}

Compact implementation of a scanning transfer cavity lock

. 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.

Scalable Bose-Einstein-condensate Sagnac interferometer in a linear trap

The loading dynamics of an alkali-atom magneto-optical trap can be used as a reliable measure of vacuum pressure, with loading time T indicating a pressure less than or equal to [2x10^(-8) Torr s]/T. This relation is accurate to approximately a factor of two over wide variations in trap parameters, background gas composition, or trapped alkali species. The low-pressure limit of the method does depend on the trap parameters, but typically extends to the 10^(-10) Torr range.

Confinement effects in a guided-wave atom interferometer with millimeter-scale arm separation

We have investigated the temperature stability of the dichroic atomic vapor laser lock laser frequency lock method. We find that, in general, the lock exhibits significant temperature sensitivity, leading to laser frequency drifts as large as tens of MHz/K. However, for certain configurations of the optical elements of the system, this temperature dependence is reduced to below 1 MHz/K. These temperature-independent points can be found across a broad range of frequencies. We present a numerical model that reproduces the general behavior of the system.

Time-orbiting potential trap for Bose-Einstein condensate interferometry

We demonstrate the effectiveness of a guided-wave Bose-Einstein condensate interferometer for practical measurements. Taking advantage of the large arm separations obtainable in our interferometer, the energy levels of the 87Rb atoms in one arm of the interferometer are shifted by a calibrated laser beam. The resulting phase shifts are used to determine the ac polarizability at a range of frequencies near and at the atomic resonance. The measured values are in good agreement with theoretical expectations. However, we observe a broadening of the transition near the resonance, an indication of collective light scattering effects. This nonlinearity may prove useful for the production and control of squeezed quantum states.

Limits on weak magnetic confinement of neutral atoms

We describe an implementation of a scanning transfer cavity laser lock that is based on a commercial optical spectrum analyzer and an inexpensive computer microcontroller. The lock performs as well as a standard saturated absorption lock for frequency differences of several GHz. It offers the advantages of locking at arbitrary frequencies, having a large capture range, and allowing complex control mechanisms to be implemented via software.

Quantum physics: An atomic SQUID

We demonstrate a two-dimensional atom interferometer in a harmonic magnetic waveguide using a Bose-Einstein condensate. Such an interferometer could measure rotation using the Sagnac effect. Compared to free space interferometers, larger interactions times and enclosed areas can in principle be achieved, since the atoms are not in free fall. In this 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. We enclose a maximum effective area of 0.1 mm{sup 2} limited by fluctuations in the initial velocity and by the coherence time of the interferometer. We argue that this arrangement is scalable to enclose larger areas by increasing the coherence time and then making repeated loops.