Atomtronic Matter-Wave Lensing.

In this Letter, we demonstrate magnetogravitational matter-wave lensing as a novel tool in atom-optics in atomtronic waveguides. We collimate and focus matter waves originating from Bose-Einstein condensates and ultracold thermal atoms in ring-shaped time-averaged adiabatic potentials. We demonstrate "delta-kick cooling" of Bose-Einstein condensates, reducing their expansion energies by a factor of 46 down to 800 pK.

Hypersonic Bose-Einstein condensates in accelerator rings.

Some of the most sensitive and precise measurements-for example, of inertia, gravity and rotation-are based on matter-wave interferometry with free-falling atomic clouds. To achieve very high sensitivities, the interrogation time has to be very long, and consequently the experimental apparatus needs to be very tall (in some cases reaching ten or even one hundred metres) or the experiments must be performed in microgravity in space. Cancelling gravitational acceleration (for example, in atomtronic circuits and matter-wave guides) is expected to result in compact devices with extended interrogation times and therefore increased sensitivity.