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Modern physics experiments are frequently very complex, relying on multiple simultaneous events to happen in order to obtain the desired result. The experiment control system plays a central role in orchestrating the measurement setup: However, its development is often treated as secondary with respect to the hardware, its importance becoming evident only during the operational phase. Therefore, the AEgIS (Antimatter Experiment: Gravity, Interferometry, Spectroscopy) collaboration has created a framework for easily coding control systems, specifically targeting atomic, quantum, and antimatter experiments. This framework, called Total Automation of LabVIEW Operations for Science (TALOS), unifies all the machines of the experiment in a single entity, thus enabling complex high-level decisions to be taken, and it is constituted by separate modules, called MicroServices, that run concurrently and asynchronously. This enhances the stability and reproducibility of the system while allowing for continuous integration and testing while the control system is running. The system demonstrated high stability and reproducibility, running completely unsupervised during the night and weekends of the data-taking campaigns. The results demonstrate the suitability of TALOS to manage an entire physics experiment in full autonomy: being open-source, experiments other than the AEgIS experiment can benefit from it.

The primary goal of the AEgIS experiment is to precisely measure the free fall of antihydrogen within Earth's gravitational field. To this end, a cold ~50K antihydrogen beam has to pass through two grids forming a moir\'e deflectometer before annihilating onto a position-sensitive detector, which shall determine the vertical position of the annihilation vertex relative to the grids with micrometric accuracy. Here we introduce a vertexing detector based on a modified mobile camera sensor and experimentally demonstrate that it can measure the position of antiproton annihilations with an accuracy of $0.62^{+0.40}_{-0.22}\mu m$, which represents a 35-fold improvement over the previous state-of-the-art for real-time antiproton vertexing. Importantly, these antiproton detection methods are directly applicable to antihydrogen. Moreover, the sensitivity to light of the sensor enables the in-situ calibration of the moir\'e deflectometer, significantly reducing systematic errors. This sensor emerges as a breakthrough technology for achieving the \aegis scientific goals and has been selected as the basis for the development of a large-area detector for conducting antihydrogen gravity measurements., Comment: 21 pages, 4 figures, 2 tables

We report on laser cooling of a large fraction of positronium (Ps) in free-flight by strongly saturating the $1^3S$-$2^3P$ transition with a broadband, long-pulsed 243 nm alexandrite laser. The ground state Ps cloud is produced in a magnetic and electric field-free environment. We observe two different laser-induced effects. The first effect is an increase in the number of atoms in the ground state after the time Ps has spent in the long-lived $3^3P$ states. The second effect is the one-dimensional Doppler cooling of Ps, reducing the cloud's temperature from 380(20) K to 170(20) K. We demonstrate a 58(9) % increase in the coldest fraction of the Ps ensemble., Comment: 6 pages, 5 figures

We propose to use table-top-size ultra-stable optical cavities from the state-of-the-art optical atomic clocks as bar gravitational wave detectors for the frequencies higher than 2 kHz. We show that 2-20 kHz range of gravitational waves' spectrum can be accessed with instruments below 2 meters in size. The proposed cavities' materials and properties are being within the present-day technology grasp. The ultra-stable optical cavities allow detecting not only predicted gravitational wave signals from such sources as binary neutron star mergers and post-mergers, subsolar-mass primordial black-hole mergers, and collapsing stellar cores, but can reach new physics beyond standard model looking for ultralight bosons such as QCD axions and axion-like particles formed through black hole superradiance.

We report the measurement of the photoionization cross sections of the 5S${}_{1/2}$ and 5P${}_{3/2}$ states of ${}^{87}$Rb in a two-species Hg and Rb magneto-optical trap (MOT) by the cooling laser for Hg. The photoionization cross sections of Rb in the 5S${}_{1/2}$ and 5P${}_{3/2}$ states at 253.7~nm are determined to be $1^{+4.3}_{-1}\times10^{-20}~\text{cm}^2$ and $4.63(30)\times 10^{-18}\text{cm}^2$, respectively. To measure the 5S${}_{1/2}$ and 5P${}_{3/2}$ states fractions in the MOT we detected photoionization rate of the 5P${}_{3/2}$ state by an additional 401.5~nm laser. The photoionization cross section of Rb in the 5P${}_{3/2}$ state at 401.5~nm is determined to be $\text{1.18(10)}\times10^{-17}~\text{cm}^2$., Comment: 9 pages, 10 figures

We report on the first earth-scale quantum sensor network based on optical atomic clocks aimed at dark matter (DM) detection. Exploiting differences in the susceptibilities to the fine-structure constant of essential parts of an optical atomic clock, i.e. the cold atoms and the optical reference cavity, we can perform sensitive searches for dark matter signatures without the need of real-time comparisons of the clocks. We report a two orders of magnitude improvement in constraints on transient variations of the fine-structure constant, which considerably improves the detection limit for the standard model (SM) - DM coupling. We use Yb and Sr optical atomic clocks at four laboratories on three continents to search for both topological defect (TD) and massive scalar field candidates. No signal consistent with a dark-matter coupling is identified, leading to significantly improved constraints on the DM-SM couplings.

We present absolute frequency measurement of the unperturbed P7 P7 O$_2$ B-band transition with relative standard uncertainty of $2\times10^{-11}$. We reached the level of accuracy typical for Doppler-free techniques, with Doppler-limited spectroscopy. The Doppler-limited shapes of the P7 P7 spectral line were measured with a frequency-stabilized cavity ring-down spectrometer referenced to an $^{88}$Sr optical atomic clock by an optical frequency comb.

The quality of Very Long Baseline Interferometry (VLBI) radio observations predominantly relies on precise and ultra-stable time and frequency (T&F) standards, usually hydrogen masers (HM), maintained locally at each VLBI station. Here, we present an operational solution in which the VLBI observations are routinely carried out without use of a local HM, but using remote synchronization via a stabilized, long-distance fibre-optic link. The T&F reference signals, traceable to international atomic timescale (TAI), are delivered to the VLBI station from a dedicated timekeeping laboratory. Moreover, we describe a proof-of-concept experiment where the VLBI station is synchronized to a remote strontium optical lattice clock during the observation., Comment: 8 pages, 8 figures, matches the version published in A&A, section Astronomical instrumentation

We present a system of two independent strontium optical lattice standards probed with a single shared ultra-narrow laser. The absolute frequency of the clocks can be verified by the use of Er:fiber optical frequency comb with the GPS-disciplined Rb frequency standard. We report hertz-level spectroscopy of the clock line and measurements of frequency stability of the two strontium optical lattice clocks., Comment: This is an author-created, un-copyedited version of an article accepted for publication in Meas. Sci. Technol. The publisher is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at doi:10.1088/0957-0233/26/7/075201

In this paper, we propose an in-depth review of the vector and tensor polarizabilities of the two energy levels of the 87Sr clock transition whose measurement was reported in [P. G. Westergaard et al., Phys. Rev. Lett. 106, 210801 (2011)]. We conduct a theoretical calculation that reproduces the measured coefficients. In addition, we detail the experimental conditions used for their measurement in two Sr optical lattice clocks, and exhibit the quadratic behaviour of the vector and tensor shifts with the depth of the trapping potential and evaluate their impact on the accuracy of the clock.

Progress in realizing the SI second had multiple technological impacts and enabled to further constraint theoretical models in fundamental physics. Caesium microwave fountains, realizing best the second according to its current definition with a relative uncertainty of 2-4x10^(-16), have already been superseded by atomic clocks referenced to an optical transition, both more stable and more accurate. Are we ready for a new definition of the second? Here we present an important step in this direction: our system of five clocks connects with an unprecedented consistency the optical and the microwave worlds. For the first time, two state-of-the-art strontium optical lattice clocks are proven to agree within their accuracy budget, with a total uncertainty of 1.6x10^(-16). Their comparison with three independent caesium fountains shows a degree of reproducibility henceforth solely limited at the level of 3.1x10^(-16) by the best realizations of the microwave-defined second., Comment: 9 pages, 4 figures, 2 tables

We describe the method allowing quantitative interpretation of absorptive images of mixtures of BEC and thermal atoms which reduces possible systematic errors associated with evaluation of the contribution of each fraction. By using known temperature dependence of the BEC fraction, the analysis allows precise calibration of the fitting results. The developed method is verified in two different measurements and compares well with theoretical calculations and with measurements performed by another group., Comment: 17 pages, 8 figures

We report on our study of the free-fall expansion of a finite-temperature Bose-Einstein condensed cloud of 87Rb. The experiments are performed with a variable total number of atoms while keeping constant the number of atoms in the condensate. The results provide evidence that the BEC dynamics depends on the interaction with thermal fraction. In particular, they provide experimental evidence that thermal cloud compresses the condensate., Comment: 8 pages, 4 figures

We report the experimental observation of a lensing effect on a Bose-Einstein condensate expanding in a moving 1D optical lattice. The effect of the periodic potential can be described by an effective mass dependent on the condensate quasi-momentum. By changing the velocity of the atoms in the frame of the optical lattice we induce a focusing of the condensate along the lattice direction. The experimental results are compared with the numerical predictions of an effective 1D theoretical model. Besides, a precise band spectroscopy of the system is carried out by looking at the real-space propagation of the atomic wavepacket in the optical lattice., Comment: 5 pages, 4 figures; minor changes applied and typos corrected; a new paragraph added; some references updated; journal reference added