Precision measurements with a two-axis cold atom gyroscope-accelerometer

This manuscript presents experimental results of a cold atom gyroscope of 11 cm² physical area, realizing the state of the art of matter wave gyroscopes. The installation of the second measurement axis in the horizontal plane allows the measurement of two components of the rotation, sequentially or interleaved. Changing the orientation of the experiment with respect to the north allowed us to perform the best test to date of the Sagnac effect for matter waves, which has been found in agreement with the expected value at the level of 20 ppm. Furthermore, the manuscript presents the proposition and the study of the interest to adjust in a controlled way the momentum transfer during Raman transitions manipulating atomic wave packets in the case of multi-loop interferometers. By preventing the recombination of spurious interferometers, this study has given the conditions to realize a pure gyroscope without any sensitivity to DC acceleration. Finally, new experimental methods have improved the rejection of the vibration noise but also of the rotation noise allowing a new stability record at 2×10⁻¹⁰ rad·s−1 at 6 000 s, and in particular by using a sequence using two interleaved interferometers allowing to average the vibrations more efficiently. Although limited in the experimental configuration, it opens the possibility to reach the intrinsic limit of cold atom inertial sensors, the quantum projection noise.

gyroscope, effet Sagnac, cold atom, atom interferometry, metrology

Full document (FR) : TEL-03828286