Text S1. The measurement sequence of the AQG-B

The measurement sequence of the AQG-B includes four main steps, that are repeated at a frequency of 1.85 Hz (Ménoret et al., 2018; Carbone et al., 2020). 1: 106 atoms are magneto-optically trapped during 270 ms and cooled down to 2 µK in optical molasses. 2: The laser is turned off and the atoms undergo a perfect free-fall. The atoms in the \(|\left.\ F=2,m_{F}=0\right\rangle\) state are selected by applying a microwave pulse, while the remaining atoms in the\(|\left.\ F=2\right\rangle\) level are blown away. 3: A Mach-Zehnder atom interferometer is operated by using a sequence of three counter-propagating stimulated Raman transitions in a\(\frac{\pi}{2}-\ \pi-\frac{\pi}{2}\) configuration, separated by an interrogation time T = 60 ms. The atomic phase shift Φ at the output of the interferometer is proportional to the gravitational acceleration g of the atoms during the free fall and scales asΦ ~ (keffg-α)T² , wherekeff is the effective wavevector of the Raman laser and α is a radio-frequency chirp applied to the Raman lasers, in order to keep the lasers on resonance and operate the atom interferometer around the null phaseshift. The atoms in each output port of the interferometer are labelled by their internal state (Bordé, 1989). 4: The proportion P ~ C/2 sin Φ of atoms in the \(|\left.\ F=2\right\rangle\) state is evaluated using a fluorescence measurement (C is the contrast of the atom interferometer).
All the operations are performed using a single 780 nm laser beam, generated through frequency-doubling of 1560 nm telecom lasers and propagated through an optical fiber to the sensor head where it is retroreflected on a hollow pyramid reflector.