Matter wave lensing to picokelvin temperatures

TL;DR

This paper demonstrates matter wave lensing techniques that cool rubidium-87 atoms to picokelvin temperatures, enabling ultra-precise quantum experiments and testing fundamental physics modifications.

Contribution

It introduces novel matter wave lensing methods achieving unprecedented ultra-low temperatures and reduces chemical potential in high-atom-number ensembles.

Findings

Achieved effective temperature below 50 pK in 2D atomic ensembles.

Implemented a short optical pulse for ensemble collimation.

Reduced chemical potential significantly in 3D magnetic lensing.

Abstract

Using a matter wave lens and a long time-of-flight, we cool an ensemble of Rb-87 atoms in two dimensions to an effective temperature of less than $50^{+50}_{-30}$~pK. A short pulse of red-detuned light generates an optical dipole force that collimates the ensemble. We also report a three-dimensional magnetic lens that substantially reduces the chemical potential of evaporatively cooled ensembles with high atom number. By observing such low temperatures, we set limits on proposed modifications to quantum mechanics in the macroscopic regime. These cooling techniques yield bright, collimated sources for precision atom interferometry.