Figure 1
Adapted from H. M√ľntinga et al. [1] and T. van Zoest et al. [12]

Figure 1: The drop tower at ZARM (left) accomodates an entire laboratory for making ultracold atomic gases in a chip trap (upper right) while freely falling from an altitude of 120 meters. After capsule release, rubidium atoms are captured in a magneto-optical trap (MOT) and then transferred to an Ioffe-Pritchard Trap (IP) where they are cooled to a Bose-Einstein condensate (BEC). Delta-kick cooling (DKC) with a pulsed magnetic field further cools the atoms to 1 nanokelvin. The ensemble is then protected from magnetic stray fields through adiabatic rapid passage (ARP) before the interferometry begins (AI). The interferometer consists of three moving Bragg grating pulses (lower right), about equally separated in time. When the atomic clouds overlap and interfere, they form macroscopic quantum fringes. Ultracold atoms in a microgravitational environment allow the realization of macroscopic quantum states over millimeter ranges and second scales.