Measuring the gravitational acceleration with precision matter-wave velocimetry

TL;DR

This paper introduces a novel atom interferometry method for measuring gravitational acceleration that eliminates the need for vibration isolation or post-correction, achieving high stability and accuracy.

Contribution

The authors develop a vibration-insensitive atom interferometry technique using velocity measurements, improving stability without external vibration control.

Findings

Achieved fractional stability of 9×10^{-6} at 1 s

Demonstrated measurement accuracy consistent with traditional gravimeters

Eliminated need for vibration isolation or post-correction

Abstract

One of the major limitations of atomic gravimeters is represented by the vibration noise of the measurement platform, which cannot be distinguished from the relevant acceleration signal. We demonstrate a new method to perform an atom interferometry measurement of the gravitational acceleration without any need for a vibration isolation system or post-corrections based on seismometer data monitoring the residual accelerations at the sensor head. With two subsequent Ramsey interferometers, we measure the velocity variation of freely falling cold atom samples, thus determining the gravitational acceleration experienced by them. Our instrument has a fractional stability of $ 9 \times 10^{-6}$ at 1 s of integration time, one order of magnitude better than a standard Mach-Zehnder interferometer when operated without any vibration isolation or applied post-correction. Using this technique, we measure the gravitational acceleration in our laboratory, which is found in good agreement with a previous determination obtained with a FG5 mechanical gravimeter.