Machine-learning-assisted material and geometry characterization from Casimir force measurement
Phys. Rev. Applied 26, 024056 – Published 20 August, 2026
DOI: https://doi.org/10.1103/11zc-ty7q
Abstract
A broadband electromagnetic source is important for scientific and technological applications. Quantum vacuum fluctuations, which manifest most prominently in the Casimir effect, provide a fundamentally broadband electromagnetic source. Here, we explore a potential consequence of the broadband nature of quantum vacuum fluctuations, by showing that such fluctuations can enable measurement of material permittivity over a broad frequency range. Specifically, we consider the Casimir force in a parallel-plate geometry, with one plate covered by a nanoscopic thin film. Using a machine learning approach, we show that one can infer both the thickness of the film and its permittivity over a broad frequency range, starting from the dependency of the Casimir forces on the spacing between the two plates. Our work highlights the application potential of using vacuum fluctuations as a naturally existing broadband electromagnetic source for material characterization and shows that the inverse problem in Casimir force calculation can be solved with machine learning.