Control of the Casimir Force Using Semiconductor Test Bodies

TL;DR

This paper reviews experimental and theoretical advances in controlling the Casimir force using semiconductor materials, including optical modulation and geometric effects, with implications for nanotechnology applications.

Contribution

It presents new experimental data on the dependence of the Casimir force on semiconductor properties and explores methods for optical and geometric control of the force.

Findings

Casimir force magnitude varies with semiconductor charge carrier concentration.

Optical modulation can change the Casimir force in the presence of laser light.

Material properties and geometry significantly influence the Casimir force behavior.

Abstract

We describe experimental and related theoretical work on the measurement of the Casimir force using semiconductor test bodies. This field of research started in 2005 and several important and interesting results have already been obtained. Specifically, the Casimir force or its gradient were measured in the configuration of an Au-coated sphere and different semiconductor surfaces. It was found that the force magnitude depends significantly on the replacement of the metal with a semiconductor and on the concentration of charge carriers in the semiconductor material. Special attention is paid to the experiment on the optical modulation of the Casimir force. In this experiment the difference Casimir force between an Au-coated sphere and Si plate in the presence and in the absence of laser light was measured. Possible applications of this experiment are discussed, specifically, for the realization of the pulsating Casimir force in three-layer systems. Theoretical problems arising from the comparison of the experimental data for the difference Casimir force with the Lifshitz theory are analyzed. We consider the possibility to control the magnitude of the Casimir force in phase transitions of semiconductor materials. Experiments on measuring the Casimir force gradient between an Au-coated sphere and Si plate covered with rectangular corrugations of different character are also described. Here, we discuss the interplay between the material properties and nontrivial geometry and the applicability of the proximity force approximation. The review contains comparison between different experiments and analysis of their advantages and disadvantages.