A quantum sensor for atom-surface interactions below 10 $\mu$m

TL;DR

This paper presents a quantum sensor using ultracold atoms in an optical lattice to measure atom-surface interactions at sub-10 micron distances with high spatial precision.

Contribution

The authors develop a novel quantum device that combines optical trapping, precise positioning, and force measurement techniques for short-range atom-surface interaction studies.

Findings

Achieved micrometer-scale positioning of ultracold atoms near surfaces.

Measured forces on atoms with micrometer spatial resolution.

Demonstrated techniques for transverse displacement and surface proximity control.

Abstract

We report about the realization of a quantum device for force sensing at micrometric scale. We trap an ultracold $^{88}$Sr atomic cloud with a 1-D optical lattice, then we place the atomic sample close to a test surface using the same optical lattice as an elevator. We demonstrate precise positioning of the sample at the $\mu$m scale. By observing the Bloch oscillations of atoms into the 1-D optical standing wave, we are able to measure the total force on the atoms along the lattice axis, with a spatial resolution of few microns. We also demonstrate a technique for transverse displacement of the atoms, allowing to perform measurements near either transparent or reflective test surfaces. In order to reduce the minimum distance from the surface, we compress the longitudinal size of the atomic sample by means of an optical tweezer. Such system is suited for studies of atom-surface interaction at short distance, such as measurement of Casimir force and search for possible non-Newtonian gravity effects.