Suspension of atoms and gravimetry using a pulsed standing wave

TL;DR

This paper demonstrates a method to suspend atoms against gravity using pulsed standing waves, enabling precise gravimetry and atom interferometry without requiring atoms to fall freely over large distances.

Contribution

It introduces a novel technique for suspending atoms with high reflection efficiency and maintains coherence for gravity measurement applications.

Findings

Achieved over 100 reflections, suspending atoms for more than 100 ms.

Implemented a gravitationally sensitive atom interferometer.

Demonstrated potential for precise gravity measurements in constrained environments.

Abstract

Atoms from an otherwise unconfined 87Rb condensate are shown to be suspended against gravity using repeated reflections from a pulsed optical standing wave. Reflection efficiency was optimized using a triple-pulse sequence that, theoretically, provides accuracies better than 99.9%. Experimentally, up to 100 reflections are observed, leading to dynamical suspension for over 100 ms. The velocity sensitivity of the reflections can be used to determine the local gravitational acceleration. Further, a gravitationally sensitive atom interferometer was implemented using the suspended atoms, with packet coherence maintained for a similar time. These techniques could be useful for the precise measurement of gravity when it is impractical to allow atoms to fall freely over a large distance.