Large Momentum Transfer Clock Atom Interferometry on the 689 nm Intercombination Line of Strontium

TL;DR

This paper demonstrates large momentum transfer clock atom interferometry using strontium atoms on the 689 nm transition, achieving high momentum separation and extended measurement durations, with potential applications in precision sensing and fundamental physics.

Contribution

First realization of large momentum transfer clock atom interferometry on strontium's intercombination line, surpassing previous momentum and duration limits with innovative techniques.

Findings

Achieved up to 141 ħk momentum separation in Mach-Zehnder interferometers.

Extended gradiometer duration to 50 times the excited state lifetime.

Performed experiments with laser-cooled atoms at 3 μK temperature.

Abstract

We report the first realization of large momentum transfer (LMT) clock atom interferometry. Using single-photon interactions on the strontium ${}^1S_0 - {}^3P_1$ transition, we demonstrate Mach-Zehnder interferometers with state-of-the-art momentum separation of up to $141\,\hbar k$ and gradiometers of up to $81\,\hbar k$. Moreover, we circumvent excited state decay limitations and extend the gradiometer duration to 50 times the excited state lifetime. Because of the broad velocity acceptance of the interferometry pulses, all experiments are performed with laser-cooled atoms at a temperature of $3\,\mu \text{K}$. This work has applications in high-precision inertial sensing and paves the way for LMT-enhanced clock atom interferometry on even narrower transitions, a key ingredient in proposals for gravitational wave detection and dark matter searches.