Casimir experiments showing saturation effects

TL;DR

This paper investigates discrepancies between theoretical predictions and experimental measurements of the Casimir force, proposing saturation effects as an explanation for the observed deviations across various experiments.

Contribution

The study introduces saturation effects as a unifying explanation for the mismatches between theory and experiment in multiple Casimir force measurements.

Findings

Saturation effects can account for the absence of predicted thermal corrections.

Saturation effects explain the larger-than-expected force changes with laser intensity.

Saturation effects reconcile the smaller-than-predicted force changes in atom-wall experiments.

Abstract

We address several different Casimir experiments where theory and experiment disagree. First out is the classical Casimir force measurement between two metal half spaces; here both in the form of the torsion pendulum experiment by Lamoreaux and in the form of the Casimir pressure measurement between a gold sphere and a gold plate as performed by Decca et al.; theory predicts a large negative thermal correction, absent in the high precision experiments. The third experiment is the measurement of the Casimir force between a metal plate and a laser irradiated semiconductor membrane as performed by Chen et al.; the change in force with laser intensity is larger than predicted by theory. The fourth experiment is the measurement of the Casimir force between an atom and a wall in the form of the measurement by Obrecht et al. of the change in oscillation frequency of a 87 Rb Bose-Einstein condensate trapped to a fused silica wall; the change is smaller than predicted by theory. We show that saturation effects can explain the discrepancies between theory and experiment observed in all these cases.