Experimental approaches to the difference in the Casimir force through the varying optical properties of boundary surface

TL;DR

This paper proposes two innovative experiments to measure how the Casimir force varies with the optical properties of boundary surfaces, using patterned semiconductors and phase-changing materials to explore theoretical and practical implications.

Contribution

It introduces novel experimental setups for measuring Casimir forces with patterned and phase-changing surfaces, addressing theoretical challenges in Lifshitz theory at finite temperatures.

Findings

First results on calibration and sensitivity of the apparatus

Calculated Casimir forces using different theoretical models

Potential to resolve theoretical issues in Casimir force calculations

Abstract

We propose two novel experiments on the measurement of the Casimir force acting between a gold coated sphere and semiconductor plates with markedly different charge carrier densities. In the first of these experiments a patterned Si plate is used which consists of two sections of different dopant densities and oscillates in the horizontal direction below a sphere. The measurement scheme in this experiment is differential, i.e., allows the direct high-precision measurement of the difference of the Casimir forces between the sphere and sections of the patterned plate or the difference of the equivalent pressures between Au and patterned parallel plates with static and dynamic techniques, respectively. The second experiment proposes to measure the Casimir force between the same sphere and a VO${}_2$ film which undergoes the insulator-metal phase transition with the increase of temperature. We report the present status of the interferometer based variable temperature apparatus developed to perform both experiments and present the first results on the calibration and sensitivity. The magnitudes of the Casimir forces and pressures in the experimental configurations are calculated using different theoretical approaches to the description of optical and conductivity properties of semiconductors at low frequencies proposed in the literature. It is shown that the suggested experiments will aid in the resolution of theoretical problems arising in the application of the Lifshitz theory at nonzero temperature to real materials. They will also open new opportunities in nanotechnology.