MAIUS - B: System status and mission goals*

Dual-species atom interferometry is a promising tool to probe hypothetical models of fundamental physics which question the validity of the weak equivalence principle. The accuracy of atom interferometric measurements scales with the square of the time between the light pulses. Thus, the accuracy of current ground-based atom interferometers employing free falling atoms is ultimately limited by the size of the apparatus. To benefit from the full potential of atom interferometry, one of the long-term goals of the scientific community is to have a dual-species atom interferometer aboard a satellite which is in continuous free fall around the Earth.

The sounding rocket missions of the MAIUS program (Matterwave Interferometry under Microgravity) aim to demonstrate dual-species atom interferometry with Rb-87 and K-41 in space.

MAIUS-1 achieved the first generation of Bose-Einstein condensate (BEC) in space with Rb-87 atoms [1], followed by studies on shear interferometry [2]. The upcoming missions MAIUS-2 and -3 will focus on two-species BEC generation and their mixture dynamics as well as simultaneous interferometry based on Raman-Double diffraction. Together with other international efforts like the Cold Atom Lab on the International Space Station and the quantum gases lab on the Tiangong Spacestation, the sounding rocket experiments provide a complementory approach towards experiments with ultracold atoms in space.

This contribution presents the current status of the system and flight preparations. Emphasis is placed on the generation of BEC mixtures, magnetic atomic transport and Delta-Kick collimation on ground. The transfer of experimental sequences from gravity into microgravity is discussed which is a central part of the mission preparation. In line with this, a careful characterization of the system parameters is needed as well as their implementation in simulation tools.

[1] D. Becker, M. D. Lachmann, S. T. Seidel et al. Nature 562, 391-395 (2018)

[2] M. D. Lachmann, H. Ahlers, D. Becker et al. Nature Comm. 12, 1317 (2021)