Ultracold atoms as a source for improving the accuracy of atom gravimeters

Franck Pereira dos Santos, Romain Karcher, Sébastien Merlet

Romain Karcher, Almazbek Imanaliev, Sébastien Merlet +1 more

We report on the implementation of ultracold atoms as a source in a state of the art atom gravimeter. We perform gravity measurements with 10 nm s −2 statistical uncertainties in a so-far largely unexplored temperature range for such a high accuracy sensor, down to 50 nK. This allows for an improved characterization of the most limiting systematic effect, related to wavefront aberrations of light beamsplitters. A thorough model of the impact of this effect onto the measurement is developed and a method is proposed to correct for this bias based on the extrapolation of the measurements down to zero temperature. Finally, an uncertainty of 13 nm s −2 is obtained in the evaluation of this systematic effect, which can be improved further by performing measurements at even lower temperatures. Our results clearly demonstrate the benefit brought by ultracold atoms to the metrological study of free falling atom interferometers. By tackling their main limitation, the method presented here allows reaching record-breaking accuracies for inertial sensors based on atom interferometry.

Sébastien Merlet, Romain Karcher, Almazbek Imanaliev +1 more

Atom interferometry allows for the realisation of inertial sensors based on laser cooled atoms. Their limits in performances, both in terms of accuracy and stability, are linked to the temperature of the atomic cloud, in the low μK range, and more specifically, to the residual ballistic expansion of the atomic sources in the laser beams. To overcome these limits, we use as a source ultracold atoms in the nano-kelvin range in our absolute atom gravimeter.

Julien Dugué

Jun Ye, Sebastian Blatt, Martin M. Boyd +8 more

Gang Xu