Frequency-dependent Drude damping in Casimir force calculations

TL;DR

This paper investigates how frequency-dependent Drude damping affects Casimir force calculations between gold thin films, revealing small but notable differences from constant damping models, especially in films thinner than 300 Å.

Contribution

It introduces a frequency-dependent damping model for gold films in Casimir force calculations, based on experimental data, and compares annealed and non-annealed film effects.

Findings

Casimir force changes by a few percent with frequency-dependent damping.

Significant effects are observed only in films thinner than 300 Å.

Frequency dependence impacts force calculations more than constant damping assumptions.

Abstract

The Casimir force is calculated between Au thin films that are described by a Drude model with a frequency dependent damping function. The model parameters are obtained from available experimental data for Au thin films. Two cases are considered; annealed and nonannealed films that have a different damping function. Compared with the calculations using a Drude model with a constant damping parameter, we observe changes in the Casimir force of a few percent. This behavior is only observed in films of no more than 300 $\AA$ thick.