Alkali adsorbate polarization on conducting and insulating surfaces probed with Bose-Einstein condensates

TL;DR

This study uses a Bose-Einstein condensate as a highly sensitive probe to measure the electric polarization and fields generated by rubidium adsorbates on different surfaces, revealing surface-dependent electrical effects.

Contribution

It introduces a novel method employing Bose-Einstein condensates to detect and analyze adsorbate-induced electrical polarization on various surfaces.

Findings

Rubidium adsorbates induce measurable electrical fields on surfaces.

Conducting and insulating surfaces show different electrical polarization behaviors.

The technique's sensitivity limits are discussed for short-range force measurements.

Abstract

A magnetically trapped 87Rb Bose-Einstein condensate is used as a sensitive probe of short-range electrical forces. In particular, the electric polarization of, and the subsequent electric field generated by, 87Rb adsorbates on conducting and insulating surfaces is measured by characterizing perturbations to the magnetic trapping potential using high-Q condensate excitations. The nature of the alterations to the electrical properties of Rb adsorbates is studied on titanium (metal) and silicon (semiconductor) surfaces, which exhibit nearly identical properties, and on glass (insulator), which displays a smaller transitory electrical effect. The limits of this technique in detecting electrical fields and ramifications for measurements of short-range forces near surfaces are discussed.