Figure 1

Benefits of microgravity for atomic physics. Different experiments in microgravity (top row) and earth-bound conditions (bottom row) are shown. In all figures, the z-axis points in the direction of gravitational acceleration g. (a) Atomic species of different masses m (red and blue) are confined in a potential. In the absence of any gravitational sag, the trapping potentials perfectly overlap, while in a gravitational field the two species experience a differential sag and the atomic clouds are (partially) separated. In addition, the traps have to be steeper than in microgravity to prevent the atoms from falling out of the confinement. (b) Both graphs show a Mach-Zehnder atom interferometer. Laser pulses coherently split, reflect, and recombine the atomic cloud. In microgravity, the atomic trajectory is only determined by the interaction with the laser pulses and long pulse-separation times T are accessible in a small setup. On ground, gravity alters the trajectory of the atoms and the free-fall distance of the atoms limits the pulse-separation time \(T'\). (c) In the absence of gravitational forces new and complex trapping geometries can be realized including shell-like 3D potentials. In an earth-bound laboratory, gravity distorts such a shell trap leading to an only partially filled shell