The Hannover very long baseline atom interferometry facility

Very Long Baseline Atom Interferometry (VLBAI) enables ground-based atomic matter-wave interferometry on large scales in space and time. With shot noise-limited instabilities better than 10−9 m/s2 at 1 s at the horizon, the Hannover VLBAI facility may compete with state-of-the-art superconducting gravimeters, while providing absolute instead of relative gravity measurements. Operated with rubidium and ytterbium simultaneously, tests of the universality of free fall at a level of parts in 10^13 and beyond are in reach. Finally, the large spatial extent of the interferometer allows one to probe the limits of coherence at macroscopic scales as well as the interplay of quantum mechanics and gravity. We report on the status of and first results obtained in the VLBAI facility which commenced operation in 2024.