Measurement of the Casimir force between a gold sphere and silicon surface with nanoscale trench arrays

TL;DR

This study measures the Casimir force between a gold sphere and a silicon surface with nanoscale trench arrays, revealing shape-dependent deviations from simple models and highlighting the influence of material properties.

Contribution

It provides experimental data on how nanoscale surface geometry affects the Casimir force, emphasizing the importance of shape and material effects in force predictions.

Findings

Force deviates from pairwise additive models at small distances.

Deviations are smaller than idealized calculations for perfect conductors.

Geometry and finite conductivity influence the Casimir force magnitude.

Abstract

We report measurements of the Casimir force between a gold sphere and a silicon surface with an array of nanoscale, rectangular corrugations using a micromechanical torsional oscillator. At distance between 150 nm and 500 nm, the measured force shows significant deviations from the pairwise additive formulism, demonstrating the strong dependence of the Casimir force on the shape of the interacting bodies. The observed deviation, however, is smaller than the calculated values for perfectly conducting surfaces, possibly due to the interplay between finite conductivity and geometry effects.