Do the laws of quantum physics still hold for macroscopic objects - this is at the heart of Schrödinger’s cat paradox - or do gravitation or yet unknown effects set a limit for massive particles? ...What is the fundamental relation between quantum physics and gravity? Ground-based experiments addressing these questions may soon face limitations due to limited free-fall times and the quality of vacuum and microgravity. The proposed mission Macroscopic Quantum Resonators (MAQRO) may overcome these limitations and allow addressing such fundamental questions. MAQRO harnesses recent developments in quantum optomechanics, high-mass matter-wave interferometry as well as state-of-the-art space technology to push macroscopic quantum experiments towards their ultimate performance limits and to open new horizons for applying quantum technology in space. The main scientific goal is to probe the vastly unexplored ‘quantum-classical’ transition for increasingly massive objects, testing the predictions of quantum theory for objects in a size and mass regime unachievable in ground-based experiments. The hardware will largely be based on available space technology. Here, we present the MAQRO proposal submitted in response to the 4th Cosmic Vision call for a medium-sized mission (M4) in 2014 of the European Space Agency (ESA) with a possible launch in 2025, and we review the progress with respect to the original MAQRO proposal for the 3rd Cosmic Vision call for a medium-sized mission (M3) in 2010. In particular, the updated proposal overcomes several critical issues of the original proposal by relying on established experimental techniques from high-mass matter-wave interferometry and by introducing novel ideas for particle loading and manipulation. Moreover, the mission design was improved to better fulfill the stringent environmental requirements for macroscopic quantum experiments.
For the study of Planck-scale modifications of the energy-momentum dispersion relation, which had been previously focused on the implications for ultrarelativistic particles, we consider the possible ...role of experiments involving nonrelativistic particles, and particularly atoms. We extend a recent result establishing that measurements of " atom-recoil frequency " can provide insight that is valuable for some theoretical models. And from a broader perspective we analyze the complementarity of the nonrelativistic and the ultrarelativistic regimes in this research area. Spinoro@gmail.com Probing the quantum-gravity realm with slow atoms 2
Gravitational waves (GWs) were observed for the first time in 2015, one century after Einstein predicted their existence. There is now growing interest to extend the detection bandwidth to low ...frequency. The scientific potential of multi-frequency GW astronomy is enormous as it would enable to obtain a more complete picture of cosmic events and mechanisms. This is a unique and entirely new opportunity for the future of astronomy, the success of which depends upon the decisions being made on existing and new infrastructures. The prospect of combining observations from the future space-based instrument LISA together with third generation ground based detectors will open the way toward multi-band GW astronomy, but will leave the infrasound (0.1-10 Hz) band uncovered. GW detectors based on matter wave interferometry promise to fill such a sensitivity gap. We propose the European Laboratory for Gravitation and Atom-interferometric Research (ELGAR), an underground infrastructure based on the latest progress in atomic physics, to study space-time and gravitation with the primary goal of detecting GWs in the infrasound band. ELGAR will directly inherit from large research facilities now being built in Europe for the study of large scale atom interferometry and will drive new pan-European synergies from top research centers developing quantum sensors. ELGAR will measure GW radiation in the infrasound band with a peak strain sensitivity of 3.3×10−22/Hz at 1.7 Hz. The antenna will have an impact on diverse fundamental and applied research fields beyond GW astronomy, including gravitation, general relativity, and geology.
Amplitude modulation of a tilted optical lattice can be used to steer the quantum transport of matter wave packets in a very flexible way. This allows the experimental study of the phase sensitivity ...in a multimode interferometer based on delocalization-enhanced Bloch oscillations and to probe the band structure modified by a constant force.
Ultra-precise optical clocks in space will allow new studies in fundamental physics and astronomy. Within an European Space Agency (ESA) program, the “Space Optical Clocks” (SOC) project aims to ...install and to operate an optical lattice clock on the International Space Station (ISS) towards the end of this decade. It would be a natural follow-on to the ACES mission, improving its performance by at least one order of magnitude. The payload is planned to include an optical lattice clock, as well as a frequency comb, a microwave link, and an optical link for comparisons of the ISS clock with ground clocks located in several countries and continents. Within the EU-FP7-SPACE-2010-1 project No. 263500, during the years 2011–2015 a compact, a modular and robust strontium lattice optical clock demonstrator has been developed. The goal performance is a fractional frequency instability below 1×10−15τ−1/2 and a fractional inaccuracy below 5 ×10−17. Here we describe the current status of the apparatus' development, including the laser subsystems. The robust preparation of cold 88Sr atoms in a second-stage magneto-optical trap (MOT) is achieved.
Des horloges optiques ultra-précises envoyées dans l'espace permettront de nouvelles avancées dans les domaines de la physique fondamentale et de l'astronomie. Le projet « Horloges optiques spatiales » (SOC pour Space Optical Clocks), qui fait partie d'un programme de l'Agence spatiale européenne (ESA), a pour but d'envoyer et de faire fonctionner une horloge à réseau optique à bord de la station spatiale internationale (ISS) vers la fin de la décennie. Cette mission serait un successeur de la mission ACES, avec une performance au moins dix fois meilleure. Il est prévu que la charge utile inclue une horloge à réseau optique ainsi qu'un peigne de fréquences, un lien micro-onde et un lien optique pour comparer cette horloge avec d'autres situées sur Terre, dans plusieurs pays et continents. Entre 2011 et 2015, un démonstrateur d'horloge à réseau optique utilisant des atomes de strontium, compact, modulaire et robuste a été développé dans le cadre du projet n∘ 263500 EU-FP7-SPACE-2010-1. La performance visée est une stabilité de fréquence fractionelle meilleure que 1×10−15τ1/2 et un exactitude fractionelle meilleure que 5×10−17. Dans cette article, nous décrivons l'état d'avancement du développement du dispositif, incluant les sous-systémes laser. La préparation d'atomes froids de 88Sr dans un piége magnéto-optique sur raie étroite est démontrée.
A symmetric Ramsey-Bordé (Mach-Zehnder geometry) atom interferometer is studied as gravitational wave detector under the hypothesis of shot noise limited sensitivity. Full gauge-invariant response ...function is deduced via ABCD matrices approach and the resulting sensitivity is analyzed in the frequency domain. As an example, a possible use in a specific frequency range is studied in some detail.
New quantum sensors based on atom interferometry make it possible to measure gravity with extreme precision. In Florence we measured the value of the gravitational constant G for the first time using ...an atom interferometer. Keywords. Atom interferometry, ultracold atoms, precision measurements, gravitational physics Nuovi sensori quantistici basati sull'interferometria atomica permettono di misurare la gravita con estrema precisione. A Firenze per la prima volta si e misurato il valore della costante gravitazionale G utilizzando un interferometro atomico. Parole chiave. Interferometria atomica, atomi ultrafreddi, misure di precisione, fisica gravitazionale.
We summarise the discussions at a virtual Community Workshop on Cold Atoms in Space concerning the status of cold atom technologies, the prospective scientific and societal opportunities offered by ...their deployment in space, and the developments needed before cold atoms could be operated in space. The cold atom technologies discussed include atomic clocks, quantum gravimeters and accelerometers, and atom interferometers. Prospective applications include metrology, geodesy and measurement of terrestrial mass change due to, e.g., climate change, and fundamental science experiments such as tests of the equivalence principle, searches for dark matter, measurements of gravitational waves and tests of quantum mechanics. We review the current status of cold atom technologies and outline the requirements for their space qualification, including the development paths and the corresponding technical milestones, and identifying possible pathfinder missions to pave the way for missions to exploit the full potential of cold atoms in space. Finally, we present a first draft of a possible road-map for achieving these goals, that we propose for discussion by the interested cold atom, Earth Observation, fundamental physics and other prospective scientific user communities, together with the European Space Agency (ESA) and national space and research funding agencies.
Atom interferometers have a multitude of proposed applications in space including precise measurements of the Earth’s gravitational field, in navigation & ranging, and in fundamental physics such as ...tests of the weak equivalence principle (WEP) and gravitational wave detection. While atom interferometers are realized routinely in ground-based laboratories, current efforts aim at the development of a space compatible design optimized with respect to dimensions, weight, power consumption, mechanical robustness and radiation hardness. In this paper, we present a design of a high-sensitivity differential dual species
85
Rb/
87
Rb atom interferometer for space, including physics package, laser system, electronics and software. The physics package comprises the atom source consisting of dispensers and a 2D magneto-optical trap (MOT), the science chamber with a 3D-MOT, a magnetic trap based on an atom chip and an optical dipole trap (ODT) used for Bose-Einstein condensate (BEC) creation and interferometry, the detection unit, the vacuum system for 10
−11
mbar ultra-high vacuum generation, and the high-suppression factor magnetic shielding as well as the thermal control system. The laser system is based on a hybrid approach using fiber-based telecom components and high-power laser diode technology and includes all laser sources for 2D-MOT, 3D-MOT, ODT, interferometry and detection. Manipulation and switching of the laser beams is carried out on an optical bench using Zerodur bonding technology. The instrument consists of 9 units with an overall mass of 221 kg, an average power consumption of 608 W (814 W peak), and a volume of 470 liters which would well fit on a satellite to be launched with a Soyuz rocket, as system studies have shown.
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