Measuring Electric Fields From Surface Contaminants with Neutral Atoms

TL;DR

This paper presents a novel method using magnetically trapped neutral atoms to measure and reconstruct electric fields from surface contaminants, improving understanding of surface-induced electric effects.

Contribution

The study introduces a technique to measure and map electric fields from surface contaminants using trapped neutral atoms, including effects of adsorbed atoms and surface treatments.

Findings

Electric fields from surface contaminants can be measured and reconstructed.

Baking the substrate reduces electric fields, likely via surface diffusion.

The method enables precise assessment of surface-induced electric effects.

Abstract

In this paper we demonstrate a technique of utilizing magnetically trapped neutral Rb-87 atoms to measure the magnitude and direction of stray electric fields emanating from surface contaminants. We apply an alternating external electric field that adds to (or subtracts from) the stray field in such a way as to resonantly drive the trapped atoms into a mechanical dipole oscillation. The growth rate of the oscillation's amplitude provides information about the magnitude and sign of the stray field gradient. Using this measurement technique, we are able to reconstruct the vector electric field produced by surface contaminants. In addition, we can accurately measure the electric fields generated from adsorbed atoms purposely placed onto the surface and account for their systematic effects, which can plague a precision surface-force measurement. We show that baking the substrate can reduce the electric fields emanating from adsorbate, and that the mechanism for reduction is likely surface diffusion, not desorption.