Atom interferometry in the transportable Quantum Gravimeter QG-1

The transportable Quantum Gravimeter QG-1 is based on the principle of atom interferometry with collimated Bose-Einstein condensates (BEC) to determine the absolute value of the local gravitational acceleration g, aiming for an unprecedented level of accuracy < 3 nm s⁻². The QG-1 uses an atom-chip to produce well-defined magnetic fields, allowing high controllability of the atomic cloud and creating a BEC. After release from the magnetic trap into free fall, using well-controlled laser pulses the BEC is split, each part accumulating phase on its trajectory during free fall, and thereafter recombined, leading to self-interference. From the phase difference of the two parts of the BEC, the local gravitational acceleration g can be determined. Environmental vibrations contribute to the accumulating phase during free fall, leading to a disturbing phase shift of the interfering BEC. By measuring the high-frequency environmental noise with a classical accelerometer, this additional phase shift can be infered and corrected for in the determination of g.
In this contribution tide-resolving results of the latest measurement campaign with implemented classical sensors to correct for high-frequency vibrations with an accelerometer and drifts with a tiltmeter will be presented, rendering an important milestone for the development of our QG-1.
We acknowledge financial funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) - Project-ID 434617780 - SFB 1464 TerraQ and under Germany’s Excellence Strategy - EXC 2123 QuantumFrontiers, Project-ID 390837967.