# Zero-velocity atom interferometry using a retroreflected frequency chirped laser

## TL;DR

This paper introduces a novel frequency chirp method in atom interferometry that enables zero-velocity atom measurements, enhancing precision in inertial sensing and microgravity applications.

## Contribution

A new technique using frequency chirping on Raman lasers lifts degeneracy in zero-velocity atom interferometry, enabling high-precision measurements.

## Key findings

- Achieved horizontal acceleration sensitivity of 3.2×10⁻⁵ m/s²/√Hz.
- Demonstrated absence of bias from the frequency chirp method.
- Potential applications in multiaxis inertial sensors and microgravity environments.

## Abstract

Atom interferometry using stimulated Raman transitions in a retroreflected configuration is the first choice in high precision measurements because it provides low phase noise, high quality Raman wavefront and simple experimental setup. However, it cannot be used for atoms at zero velocity because two pairs of Raman lasers are simultaneously resonant. Here we report a method which allows to lift this degeneracy by using a frequency chirp on the Raman lasers. Using this technique, we realize a Mach-Zehnder atom interferometer hybridized with a force balanced accelerometer which provides horizontal acceleration measurements with a short-term sensitivity of $3.2\times 10^{-5}$ m.s$^{-2}$/$\sqrt{Hz}$. We check at the level of precision of our experiment the absence of bias induced by this method. This technique could be used for multiaxis inertial sensors, tiltmeters or atom interferometry in a microgravity environment.