UCLA

This dissertation details the construction of a neutral ultracold atom system along with one completed experiment and one future experiment. This systems contains a two-stage slowing/cooling scheme with a Zeeman slower and a magneto-optical trap (MOT), as well as an in-vacuum optical cavity. The optical cavity was specially designed for precision measurement experiments. When near resonance atoms are present in the cavity, they cause a phase shift in the light. This enables use of the cavity light transmission as a minimally invasive feedback for information on the presence of atoms in the cavity. We look at this atom cavity interaction in two regimes: a deep lattice and a shallow lattice.

Atoms confined to a deep optical lattice are constrained to thousands of individual wells. Any feedback on the lattice from motion of atoms in a single well is amplified by thousands due to this repetition. We exploit this deep lattice uniformity to measure atomic motion immediately after release from the deep lattice using another very shallow probe lattice. The feedback from the atomic motion on the probe lattice cavity transmission is used to measure the atomic sample’s original temperature without losing the atoms. We measure the sample's temperature in both the axial and radial direction, with the axial measurement taking $<10~\mu$s with the ability to recapture $75\%$ of the atoms back into the lattice.

Atoms in a shallow lattice have wavefunctions spread out across multiple lattice cites. This enables them to undergo a process called Bloch oscillations, which requires a periodic potential plus a uniform force (gravity). I perform a simulation of the coupled atom and lattice distributions to optimize our experimental realization of the system. The atomic oscillations due to gravity imprint their oscillation frequency on the transmission of cavity light, which enables us to measure the force on the atoms which is directly proportional to the frequency. We plan on using this feature to perform a precision measurement on our atoms to look for ultralight dark matter. I estimate our limits on this type of dark matter, and discuss the future of this experiment.