Direct Measurement of intermediate-range Casimir-Polder potentials

TL;DR

This paper reports the first direct measurements of Casimir-Polder forces in the intermediate regime using ultracold Rb atoms reflected from evanescent wave barriers, confirming theoretical predictions without assuming potential shape.

Contribution

It introduces a novel experimental method for directly measuring Casimir-Polder forces in the transition regime between electrostatic and retarded limits.

Findings

Experimental data confirms theoretical predictions in the transition regime.

Method does not require assumptions about potential shape.

First direct measurement of intermediate-range Casimir-Polder forces.

Abstract

We present the first direct measurements of Casimir-Polder forces between solid surfaces and atomic gases in the transition regime between the electrostatic short-distance and the retarded long-distance limit. The experimental method is based on ultracold ground-state Rb atoms that are reflected from evanescent wave barriers at the surface of a dielectric glass prism. Our novel approach does not require assumptions about the potential shape. The experimental data confirm the theoretical prediction in the transition regime.