Comparison of hydrodynamic model of graphene with recent experiment on measuring the Casimir interaction

TL;DR

This study compares the hydrodynamic and Dirac models of graphene in predicting the Casimir force, finding experimental data strongly supports the Dirac model and excludes the hydrodynamic model.

Contribution

The paper provides a direct comparison between hydrodynamic and Dirac models of graphene for Casimir interactions, validating the Dirac model with experimental data.

Findings

Hydrodynamic model is excluded at 99% confidence level.

Dirac model agrees well with experimental measurements.

Confirms low-energy nature of Casimir interaction in graphene.

Abstract

We obtain the reflection coefficients from a graphene sheet deposited on a material substrate under a condition that graphene is described by the hydrodynamic model. Using these coefficients, the gradient of the Casimir force in the configuration of recent experiment is calculated in the framework of the Lifshitz theory. It is shown that the hydrodynamic model is excluded by the measurement data at the 99% confidence level over a wide range of separations. From the fact that the same data are in a very good agreement with theoretical predictions of the Dirac model of graphene, the low-energy character of the Casimir interaction is confirmed.